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Sunday, March 5, 2023

Inflation

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Inflation

Inflation rates among members of the International Monetary Fund in October 2022.
 
UK and US monthly inflation rates from January 1989 to the present.

In economics, inflation is an increase in the general price level of goods and services in an economy. When the general price level rises, each unit of currency buys fewer goods and services; consequently, inflation corresponds to a reduction in the purchasing power of money. The opposite of inflation is deflation, a decrease in the general price level of goods and services. The common measure of inflation is the inflation rate, the annualized percentage change in a general price index. As prices faced by households do not all increase at the same rate, the consumer price index (CPI) is often used for this purpose. The employment cost index is also used for wages in the United States.

Most economists agree that high levels of inflation as well as hyperinflation—which have severely disruptive effects on the real economy—are caused by persistent excessive growth in the money supply. Views on low to moderate rates of inflation are more varied. Low or moderate inflation may be attributed to fluctuations in real demand for goods and services, or changes in available supplies such as during scarcities. Moderate inflation affects economies in both positive and negative ways. The negative effects would include an increase in the opportunity cost of holding money, uncertainty over future inflation which may discourage investment and savings, and if inflation were rapid enough, shortages of goods as consumers begin hoarding out of concern that prices will increase in the future. Positive effects include reducing unemployment due to nominal wage rigidity, allowing the central bank greater freedom in carrying out monetary policy, encouraging loans and investment instead of money hoarding, and avoiding the inefficiencies associated with deflation.

Today, most economists favour a low and steady rate of inflation. Low (as opposed to zero or negative) inflation reduces the probability of economic recessions by enabling the labor market to adjust more quickly in a downturn and reduces the risk that a liquidity trap prevents monetary policy from stabilizing the economy, while avoiding the costs associated with high inflation. The task of keeping the rate of inflation low and stable is usually given to monetary authorities. Generally, these monetary authorities are the central banks that control monetary policy through the setting of interest rates, by carrying out open market operations and (more rarely) changing commercial bank reserve requirements.

Terminology

The term originates from the Latin inflare (to blow into or inflate) and was initially used in America in 1838 with regard to inflating the currency. The term was used "not in reference to something that happens to prices, but as something that happens to a paper currency". The resulting imbalance between the quantity of money and the amount needed for trade caused prices to increase. Over time, the term inflation has evolved to refer to increases in the price level; an increase in the money supply may be called monetary inflation to distinguish it from rising prices, which for clarity may be called "price inflation".

Conceptually, inflation refers to the general trend of prices, not changes in any specific price. For example, if people choose to buy more cucumbers than tomatoes, cucumbers consequently become more expensive and tomatoes cheaper. These changes are not related to inflation; they reflect a shift in tastes. Inflation is related to the value of currency itself. When currency was linked with gold, if new gold deposits were found, the price of gold and the value of currency would fall, and consequently, prices of all other goods would become higher.

Classical economics

By the nineteenth century, economists categorised three separate factors that cause a rise or fall in the price of goods: a change in the value or production costs of the good, a change in the price of money which then was usually a fluctuation in the commodity price of the metallic content in the currency, and currency depreciation resulting from an increased supply of currency relative to the quantity of redeemable metal backing the currency. Following the proliferation of private banknote currency printed during the American Civil War, the term "inflation" started to appear as a direct reference to the currency depreciation that occurred as the quantity of redeemable banknotes outstripped the quantity of metal available for their redemption. At that time, the term inflation referred to the devaluation of the currency, and not to a rise in the price of goods. This relationship between the over-supply of banknotes and a resulting depreciation in their value was noted by earlier classical economists such as David Hume and David Ricardo, who would go on to examine and debate what effect a currency devaluation (later termed monetary inflation) has on the price of goods (later termed price inflation, and eventually just inflation).

Related concepts

Other economic concepts related to inflation include: deflation – a fall in the general price level; disinflation – a decrease in the rate of inflation; hyperinflation – an out-of-control inflationary spiral; stagflation – a combination of inflation, slow economic growth and high unemployment; reflation – an attempt to raise the general level of prices to counteract deflationary pressures; and asset price inflation – a general rise in the prices of financial assets without a corresponding increase in the prices of goods or services; agflation – an advanced increase in the price for food and industrial agricultural crops when compared with the general rise in prices.

More specific forms of inflation refer to sectors whose prices vary semi-independently from the general trend. “House price inflation” applies to changes in the house price index while “energy inflation” is dominated by the costs of oil and gas.

History

US historical inflation (in blue) and deflation (in green) from the mid-17th century to the beginning of the 21st.

Historically, when commodity money was used, periods of inflation and deflation would alternate depending on the condition of the economy. However, when large prolonged infusions of gold or silver into an economy occurred, this could lead to long periods of inflation.

The adoption of fiat currency by many countries, from the 18th century onwards, made much larger variations in the supply of money possible. Rapid increases in the money supply have taken place a number of times in countries experiencing political crises, producing hyperinflations – episodes of extreme inflation rates much higher than those observed in earlier periods of commodity money. The hyperinflation in the Weimar Republic of Germany is a notable example. Currently, the hyperinflation in Venezuela is the highest in the world, with an annual inflation rate of 833,997% as of October 2018.

Historically, inflations of varying magnitudes have occurred from the price revolution of the 16th century, which was driven by the flood of gold and particularly silver seized and mined by the Spaniards in Latin America, to the largest paper money inflation of all time in Hungary after World War II.

However, since the 1980s, inflation has been held low and stable in countries with independent central banks. This has led to a moderation of the business cycle and a reduction in variation in most macroeconomic indicators – an event known as the Great Moderation.

Historical inflationary periods

Silver purity through time in early Roman imperial silver coins. To increase the number of silver coins in circulation while short on silver, the Roman imperial government repeatedly debased the coins. They melted relatively pure silver coins and then struck new silver coins of lower purity but of nominally equal value. Silver coins were relatively pure before Nero (AD 54-68), but by the 270s had hardly any silver left.
 
The silver content of Roman silver coins rapidly declined during the Crisis of the Third Century.

Rapid increases in the quantity of money or in the overall money supply have occurred in many different societies throughout history, changing with different forms of money used. For instance, when silver was used as currency, the government could collect silver coins, melt them down, mix them with other metals such as copper or lead and reissue them at the same nominal value, a process known as debasement. At the ascent of Nero as Roman emperor in AD 54, the denarius contained more than 90% silver, but by the 270s hardly any silver was left. By diluting the silver with other metals, the government could issue more coins without increasing the amount of silver used to make them. When the cost of each coin is lowered in this way, the government profits from an increase in seigniorage. This practice would increase the money supply but at the same time the relative value of each coin would be lowered. As the relative value of the coins becomes lower, consumers would need to give more coins in exchange for the same goods and services as before. These goods and services would experience a price increase as the value of each coin is reduced.

Ancient China

Song dynasty China introduced the practice of printing paper money to create fiat currency. During the Mongol Yuan dynasty, the government spent a great deal of money fighting costly wars, and reacted by printing more money, leading to inflation. Fearing the inflation that plagued the Yuan dynasty, the Ming dynasty initially rejected the use of paper money, and reverted to using copper coins.

Medieval Egypt

During the Malian king Mansa Musa's hajj to Mecca in 1324, he was reportedly accompanied by a camel train that included thousands of people and nearly a hundred camels. When he passed through Cairo, he spent or gave away so much gold that it depressed its price in Egypt for over a decade, reducing its purchasing power. A contemporary Arab historian remarked about Mansa Musa's visit:

Gold was at a high price in Egypt until they came in that year. The mithqal did not go below 25 dirhams and was generally above, but from that time its value fell and it cheapened in price and has remained cheap till now. The mithqal does not exceed 22 dirhams or less. This has been the state of affairs for about twelve years until this day by reason of the large amount of gold which they brought into Egypt and spent there [...].

— Chihab Al-Umari, Kingdom of Mali

"Price revolution" in Western Europe

From the second half of the 15th century to the first half of the 17th, Western Europe experienced a major inflationary cycle referred to as the "price revolution", with prices on average rising perhaps sixfold over 150 years. This is often attributed to the influx of gold and silver from the New World into Habsburg Spain, with wider availability of silver in previously cash-starved Europe causing widespread inflation. European population rebound from the Black Death began before the arrival of New World metal, and may have begun a process of inflation that New World silver compounded later in the 16th century.

Measures

PPI is a leading indicator, CPI and PCE lag
  PPI
  Core PPI
  CPI
  Core CPI
  PCE
  Core PCE

Given that there are many possible measures of the price level, there are many possible measures of price inflation. Most frequently, the term "inflation" refers to a rise in a broad price index representing the overall price level for goods and services in the economy. The Consumer Price Index (CPI), the Personal consumption expenditures price index (PCEPI) and the GDP deflator are some examples of broad price indices. However, "inflation" may also be used to describe a rising price level within a narrower set of assets, goods or services within the economy, such as commodities (including food, fuel, metals), tangible assets (such as real estate), services (such as entertainment and health care), or labor. Although the values of capital assets are often casually said to "inflate," this should not be confused with inflation as a defined term; a more accurate description for an increase in the value of a capital asset is appreciation. The FBI (CCI), the Producer Price Index, and Employment Cost Index (ECI) are examples of narrow price indices used to measure price inflation in particular sectors of the economy. Core inflation is a measure of inflation for a subset of consumer prices that excludes food and energy prices, which rise and fall more than other prices in the short term. The Federal Reserve Board pays particular attention to the core inflation rate to get a better estimate of long-term future inflation trends overall.

The inflation rate is most widely calculated by determining the movement or change in a price index, typically the consumer price index. The inflation rate is the percentage change of a price index over time. The Retail Prices Index is also a measure of inflation that is commonly used in the United Kingdom. It is broader than the CPI and contains a larger basket of goods and services.

Given the recent high inflation, the RPI is indicative of the experiences of a wide range of household types, particularly low-income households.

To illustrate the method of calculation, in January 2007, the U.S. Consumer Price Index was 202.416, and in January 2008 it was 211.080. The formula for calculating the annual percentage rate inflation in the CPI over the course of the year is: The resulting inflation rate for the CPI in this one-year period is 4.28%, meaning the general level of prices for typical U.S. consumers rose by approximately four percent in 2007.

Other widely used price indices for calculating price inflation include the following:

  • Producer price indices (PPIs) which measures average changes in prices received by domestic producers for their output. This differs from the CPI in that price subsidization, profits, and taxes may cause the amount received by the producer to differ from what the consumer paid. There is also typically a delay between an increase in the PPI and any eventual increase in the CPI. Producer price index measures the pressure being put on producers by the costs of their raw materials. This could be "passed on" to consumers, or it could be absorbed by profits, or offset by increasing productivity. In India and the United States, an earlier version of the PPI was called the Wholesale price index.
  • Commodity price indices, which measure the price of a selection of commodities. In the present commodity price indices are weighted by the relative importance of the components to the "all in" cost of an employee.
  • Core price indices: because food and oil prices can change quickly due to changes in supply and demand conditions in the food and oil markets, it can be difficult to detect the long run trend in price levels when those prices are included. Therefore, most statistical agencies also report a measure of 'core inflation', which removes the most volatile components (such as food and oil) from a broad price index like the CPI. Because core inflation is less affected by short run supply and demand conditions in specific markets, central banks rely on it to better measure the inflationary effect of current monetary policy.

Other common measures of inflation are:

  • GDP deflator is a measure of the price of all the goods and services included in gross domestic product (GDP). The US Commerce Department publishes a deflator series for US GDP, defined as its nominal GDP measure divided by its real GDP measure.

  • Regional inflation The Bureau of Labor Statistics breaks down CPI-U calculations down to different regions of the US.
  • Historical inflation Before collecting consistent econometric data became standard for governments, and for the purpose of comparing absolute, rather than relative standards of living, various economists have calculated imputed inflation figures. Most inflation data before the early 20th century is imputed based on the known costs of goods, rather than compiled at the time. It is also used to adjust for the differences in real standard of living for the presence of technology.
  • Asset price inflation is an undue increase in the prices of real assets, such as real estate.

Issues in measuring

Measuring inflation in an economy requires objective means of differentiating changes in nominal prices on a common set of goods and services, and distinguishing them from those price shifts resulting from changes in value such as volume, quality, or performance. For example, if the price of a can of corn changes from $0.90 to $1.00 over the course of a year, with no change in quality, then this price difference represents inflation. This single price change would not, however, represent general inflation in an overall economy. To measure overall inflation, the price change of a large "basket" of representative goods and services is measured. This is the purpose of a price index, which is the combined price of a "basket" of many goods and services. The combined price is the sum of the weighted prices of items in the "basket". A weighted price is calculated by multiplying the unit price of an item by the number of that item the average consumer purchases. Weighted pricing is a necessary means to measuring the effect of individual unit price changes on the economy's overall inflation. The Consumer Price Index, for example, uses data collected by surveying households to determine what proportion of the typical consumer's overall spending is spent on specific goods and services, and weights the average prices of those items accordingly. Those weighted average prices are combined to calculate the overall price. To better relate price changes over time, indexes typically choose a "base year" price and assign it a value of 100. Index prices in subsequent years are then expressed in relation to the base year price. While comparing inflation measures for various periods one has to take into consideration the base effect as well.

Inflation measures are often modified over time, either for the relative weight of goods in the basket, or in the way in which goods and services from the present are compared with goods and services from the past. Basket weights are updated regularly, usually every year, to adapt to changes in consumer behavior. Sudden changes in consumer behavior can still introduce a weighting bias in inflation measurement. For example, during the COVID-19 pandemic it has been shown that the basket of goods and services was no longer representative of consumption during the crisis, as numerous goods and services could no longer be consumed due to government containment measures (“lock-downs”).

Over time, adjustments are also made to the type of goods and services selected to reflect changes in the sorts of goods and services purchased by 'typical consumers'. New products may be introduced, older products disappear, the quality of existing products may change, and consumer preferences can shift. Both the sorts of goods and services which are included in the "basket" and the weighted price used in inflation measures will be changed over time to keep pace with the changing marketplace. Different segments of the population may naturally consume different "baskets" of goods and services and may even experience different inflation rates. It is argued that companies have put more innovation into bringing down prices for wealthy families than for poor families.

Inflation numbers are often seasonally adjusted to differentiate expected cyclical cost shifts. For example, home heating costs are expected to rise in colder months, and seasonal adjustments are often used when measuring for inflation to compensate for cyclical spikes in energy or fuel demand. Inflation numbers may be averaged or otherwise subjected to statistical techniques to remove statistical noise and volatility of individual prices.

When looking at inflation, economic institutions may focus only on certain kinds of prices, or special indices, such as the core inflation index which is used by central banks to formulate monetary policy.

Most inflation indices are calculated from weighted averages of selected price changes. This necessarily introduces distortion, and can lead to legitimate disputes about what the true inflation rate is. This problem can be overcome by including all available price changes in the calculation, and then choosing the median value. In some other cases, governments may intentionally report false inflation rates; for instance, during the presidency of Cristina Kirchner (2007–2015) the government of Argentina was criticised for manipulating economic data, such as inflation and GDP figures, for political gain and to reduce payments on its inflation-indexed debt.

Inflation expectations

Inflation expectations or expected inflation is the rate of inflation that is anticipated for some time in the foreseeable future. There are two major approaches to modeling the formation of inflation expectations. Adaptive expectations models them as a weighted average of what was expected one period earlier and the actual rate of inflation that most recently occurred. Rational expectations models them as unbiased, in the sense that the expected inflation rate is not systematically above or systematically below the inflation rate that actually occurs.

A long-standing survey of inflation expectations is the University of Michigan survey.

Inflation expectations affect the economy in several ways. They are more or less built into nominal interest rates, so that a rise (or fall) in the expected inflation rate will typically result in a rise (or fall) in nominal interest rates, giving a smaller effect if any on real interest rates. In addition, higher expected inflation tends to be built into the rate of wage increases, giving a smaller effect if any on the changes in real wages. Moreover, the response of inflationary expectations to monetary policy can influence the division of the effects of policy between inflation and unemployment (see Monetary policy credibility).

Causes

Historically, a great deal of economic literature was concerned with the question of what causes inflation and what effect it has. There were different schools of thought as to the causes of inflation; most historical theories can be divided into two broad areas: quality theories of inflation and quantity theories of inflation. The quality theory of inflation rests on the expectation of a seller accepting currency to be able to exchange that currency at a later time for goods they desire as a buyer. The quantity theory of inflation rests on the quantity equation of money that relates the money supply, its velocity, and the nominal value of exchanges.

Currently, the quantity theory of money is widely accepted as an accurate model of inflation in the long run. Consequently, there is now broad agreement among economists that in the long run, the inflation rate is essentially dependent on the growth rate of the money supply relative to the growth of the economy. However, in the short and medium term inflation may be affected by supply and demand pressures in the economy, and influenced by the relative elasticity of wages, prices and interest rates.

The question of whether the short-term effects last long enough to be important is the central topic of debate between monetarist and Keynesian economists. In monetarism prices and wages adjust quickly enough to make other factors merely marginal behavior on a general trend-line. In the Keynesian view, interest rates, prices, and wages adjust at different rates, and these differences have enough effects on real output to be "long term" in the view of people in an economy.

Keynesian view

Keynesian economics proposes that changes in the money supply do not directly affect prices in the short run, and that visible inflation is the result of demand pressures in the economy expressing themselves in prices.

There are three major sources of inflation, as part of what Robert J. Gordon calls the "triangle model":

  • Demand-pull inflation is caused by increases in aggregate demand due to increased private and government spending, etc. Demand inflation encourages economic growth since the excess demand and favourable market conditions will stimulate investment and expansion.
  • Cost-push inflation, also called "supply shock inflation," is caused by a drop in aggregate supply (potential output). This may be due to natural disasters, war or increased prices of inputs. For example, a sudden decrease in the supply of oil, leading to increased oil prices, can cause cost-push inflation. Producers for whom oil is a part of their costs could then pass this on to consumers in the form of increased prices. Another example stems from unexpectedly high insured losses, either legitimate (catastrophes) or fraudulent (which might be particularly prevalent in times of recession). High inflation can prompt employees to demand rapid wage increases, to keep up with consumer prices. In the cost-push theory of inflation, rising wages in turn can help fuel inflation. In the case of collective bargaining, wage growth will be set as a function of inflationary expectations, which will be higher when inflation is high. This can cause a wage spiral. In a sense, inflation begets further inflationary expectations, which beget further inflation.
  • Built-in inflation is induced by adaptive expectations, and is often linked to the "price/wage spiral". It involves workers trying to keep their wages up with prices (above the rate of inflation), and firms passing these higher labor costs on to their customers as higher prices, leading to a feedback loop. Built-in inflation reflects events in the past, and so might be seen as hangover inflation.

Demand-pull theory states that inflation accelerates when aggregate demand increases beyond the ability of the economy to produce (its potential output). Hence, any factor that increases aggregate demand can cause inflation. However, in the long run, aggregate demand can be held above productive capacity only by increasing the quantity of money in circulation faster than the real growth rate of the economy. Another (although much less common) cause can be a rapid decline in the demand for money, as happened in Europe during the Black Death, or in the Japanese occupied territories just before the defeat of Japan in 1945.

The effect of money on inflation is most obvious when governments finance spending in a crisis, such as a civil war, by printing money excessively. This sometimes leads to hyperinflation, a condition where prices can double in a month or even daily. The money supply is also thought to play a major role in determining moderate levels of inflation, although there are differences of opinion on how important it is. For example, monetarist economists believe that the link is very strong; Keynesian economists, by contrast, typically emphasize the role of aggregate demand in the economy rather than the money supply in determining inflation. That is, for Keynesians, the money supply is only one determinant of aggregate demand.

Some Keynesian economists also disagree with the notion that central banks fully control the money supply, arguing that central banks have little control, since the money supply adapts to the demand for bank credit issued by commercial banks. This is known as the theory of endogenous money, and has been advocated strongly by post-Keynesians as far back as the 1960s. This position is not universally accepted – banks create money by making loans, but the aggregate volume of these loans diminishes as real interest rates increase. Thus, central banks can influence the money supply by making money cheaper or more expensive, thus increasing or decreasing its production.

A fundamental concept in inflation analysis is the relationship between inflation and unemployment, called the Phillips curve. This model suggests that there is a trade-off between price stability and employment. Therefore, some level of inflation could be considered desirable to minimize unemployment. The Phillips curve model described the U.S. experience well in the 1960s but failed to describe the stagflation experienced in the 1970s. Thus, modern macroeconomics describes inflation using a Phillips curve that is able to shift due to such matters as supply shocks and structural inflation. The former refers to such events like the 1973 oil crisis, while the latter refers to the price/wage spiral and inflationary expectations implying that inflation is the new normal. Thus, the Phillips curve represents only the demand-pull component of the triangle model.

Another concept of note is the potential output (sometimes called the "natural gross domestic product"), a level of GDP, where the economy is at its optimal level of production given institutional and natural constraints. (This level of output corresponds to the Non-Accelerating Inflation Rate of Unemployment, NAIRU, or the "natural" rate of unemployment or the full-employment unemployment rate.) If GDP exceeds its potential (and unemployment is below the NAIRU), the theory says that inflation will accelerate as suppliers increase their prices and built-in inflation worsens. If GDP falls below its potential level (and unemployment is above the NAIRU), inflation will decelerate as suppliers attempt to fill excess capacity, cutting prices and undermining built-in inflation.

However, one problem with this theory for policy-making purposes is that the exact level of potential output (and of the NAIRU) is generally unknown and tends to change over time. Inflation also seems to act in an asymmetric way, rising more quickly than it falls. It can change because of policy: for example, high unemployment under British Prime Minister Margaret Thatcher might have led to a rise in the NAIRU (and a fall in potential) because many of the unemployed found themselves as structurally unemployed, unable to find jobs that fit their skills. A rise in structural unemployment implies that a smaller percentage of the labor force can find jobs at the NAIRU, where the economy avoids crossing the threshold into the realm of accelerating inflation.

Unemployment

A connection between inflation and unemployment has been drawn since the emergence of large scale unemployment in the 19th century, and connections continue to be drawn today. However, the unemployment rate generally only affects inflation in the short-term but not the long-term. In the long term, the velocity of money is far more predictive of inflation than low unemployment.

In Marxian economics, the unemployed serve as a reserve army of labor, which restrain wage inflation. In the 20th century, similar concepts in Keynesian economics include the NAIRU (Non-Accelerating Inflation Rate of Unemployment) and the Phillips curve.

Profiteering under consolidation

U.S. corporate profits as a proportion of GDP (blue) and year-over-year change in the Consumer Price Index (red) 2017-2022

Keynesian price inelasticity can contribute to inflation when firms consolidate, tending to support monopoly or monopsony conditions anywhere along the supply chain for goods or services. When this occurs, firms can provide greater shareholder value by taking a larger proportion of profits than by investing in providing greater volumes of their outputs.

US prices of crude oil and gasoline in February and March, 2022

Examples include the rise in gasoline and other fossil fuel prices in the first quarter of 2022. Shortly after initial energy price shocks caused by the 2022 Russian invasion of Ukraine subsided, oil companies found that supply chain constrictions, already exacerbated by the ongoing global COVID-19 pandemic, supported price inelasticity, i.e., they began lowering prices to match the price of oil when it fell much more slowly than they had increased their prices when costs rose. California's five largest gasoline companies, Chevron Corporation, Marathon Petroleum, Valero Energy, PBF Energy, and Phillips 66, responsible for 96% of transportation fuel sold in the state, all participated in this behavior, reaping first quarter profits much larger than any of their quarterly results in the previous several years. On May 19, 2022, the U.S. House of Representatives passed a bill to prevent such "price gouging" by addressing the resulting windfall profits, but it is unlikely to prevail against the minority filibuster challenge in the Senate.

Similarly in the first quarter of 2022, meatpacking giant Tyson Foods relied on downward price inelasticity in packaged chicken and related products to increase their profits to about $500 million, responding to a $1.5 billion increase in their costs with almost $2 billion in price hikes. Tyson's three main competitors, having essentially no ability to compete on lower prices because supply chain constriction would not support an increase in volumes, followed suit. Tyson's quarter was one of their most profitable, expanding their operating margin 38%. UBS Global Wealth Management chief economist Paul Donovan said this has happened because post-pandemic household balance sheets have kept consumer spending demand strong enough to encourage producers to raise prices faster than costs, and because consumers have been gullible enough to find exaggerated narratives justifying such price hikes plausible.

Effect of economic growth

If economic growth matches the growth of the money supply, inflation should not occur when all else is equal. A large variety of factors can affect the rate of both. For example, investment in market production, infrastructure, education, and preventive health care can all grow an economy in greater amounts than the investment spending.

Monetarist view

CPI 1914-2022
  Inflation
  M2 money supply increases Year/Year
 
Inflation and the growth of money supply (M2)
 

Monetarists believe the most significant factor influencing inflation or deflation is how fast the money supply grows or shrinks. They consider fiscal policy, or government spending and taxation, as ineffective in controlling inflation. The monetarist economist Milton Friedman famously stated, "Inflation is always and everywhere a monetary phenomenon."

Monetarists assert that the empirical study of monetary history shows that inflation has always been a monetary phenomenon. The quantity theory of money, simply stated, says that any change in the amount of money in a system will change the price level. This theory begins with the equation of exchange:

where

is the nominal quantity of money;
is the velocity of money in final expenditures;
is the general price level;
is an index of the real value of final expenditures;

In this formula, the general price level is related to the level of real economic activity (Q), the quantity of money (M) and the velocity of money (V). The formula is an identity because the velocity of money (V) is defined to be the ratio of final nominal expenditure () to the quantity of money (M).

Monetarists assume that the velocity of money is unaffected by monetary policy (at least in the long run), and the real value of output is determined in the long run by the productive capacity of the economy. Under these assumptions, the primary driver of the change in the general price level is changes in the quantity of money. With exogenous velocity (that is, velocity being determined externally and not being influenced by monetary policy), the money supply determines the value of nominal output (which equals final expenditure) in the short run.

In practice, velocity is not exogenous in the short run, and so the formula does not necessarily imply a stable short-run relationship between the money supply and nominal output. However, in the long run, changes in velocity are assumed to be determined by the evolution of the payments mechanism. If velocity is relatively unaffected by monetary policy, the long-run rate of increase in prices (the inflation rate) is equal to the long-run growth rate of the money supply plus the exogenous long-run rate of velocity growth minus the long run growth rate of real output.

Rational expectations theory

Rational expectations theory holds that economic actors look rationally into the future when trying to maximize their well-being, and do not respond solely to immediate opportunity costs and pressures. In this view, while generally grounded in monetarism, future expectations and strategies are important for inflation as well.

A core assertion of rational expectations theory is that actors will seek to "head off" central-bank decisions by acting in ways that fulfill predictions of higher inflation. This means that central banks must establish their credibility in fighting inflation, or economic actors will make bets that the central bank will expand the money supply rapidly enough to prevent recession, even at the expense of exacerbating inflation. Thus, if a central bank has a reputation as being "soft" on inflation, when it announces a new policy of fighting inflation with restrictive monetary growth economic agents will not believe that the policy will persist; their inflationary expectations will remain high, and so will inflation. On the other hand, if the central bank has a reputation of being "tough" on inflation, then such a policy announcement will be believed and inflationary expectations will come down rapidly, thus allowing inflation itself to come down rapidly with minimal economic disruption.

Heterodox views

Additionally, there are theories about inflation accepted by economists outside of the mainstream.

Austrian view

The Austrian School stresses that inflation is not uniform over all assets, goods, and services. Inflation depends on differences in markets and on where newly created money and credit enter the economy. Ludwig von Mises said that inflation should refer to an increase in the quantity of money, that is not offset by a corresponding increase in the need for money, and that price inflation will necessarily follow, always leaving a poorer nation.

Real bills doctrine

The real bills doctrine (RBD) asserts that banks should issue their money in exchange for short-term real bills of adequate value. As long as banks only issue a dollar in exchange for assets worth at least a dollar, the issuing bank's assets will naturally move in step with its issuance of money, and the money will hold its value. Should the bank fail to get or maintain assets of adequate value, then the bank's money will lose value, just as any financial security will lose value if its asset backing diminishes. The real bills doctrine (also known as the backing theory) thus asserts that inflation results when money outruns its issuer's assets. The quantity theory of money, in contrast, claims that inflation results when money outruns the economy's production of goods.

Currency and banking schools of economics argue the RBD, that banks should also be able to issue currency against bills of trading, which is "real bills" that they buy from merchants. This theory was important in the 19th century in debates between "Banking" and "Currency" schools of monetary soundness, and in the formation of the Federal Reserve. In the wake of the collapse of the international gold standard post 1913, and the move towards deficit financing of government, RBD has remained a minor topic, primarily of interest in limited contexts, such as currency boards. It is generally held in ill repute today, with Frederic Mishkin, a governor of the Federal Reserve going so far as to say it had been "completely discredited."

The debate between currency, or quantity theory, and the banking schools during the 19th century prefigures current questions about the credibility of money in the present. In the 19th century, the banking schools had greater influence in policy in the United States and Great Britain, while the currency schools had more influence "on the continent", that is in non-British countries, particularly in the Latin Monetary Union and the Scandinavian Monetary Union.

In 2019 monetary historians Thomas M. Humphrey and Richard H. Timberlake published "Gold, the Real Bills Doctrine, and the Fed: Sources of Monetary Disorder 1922-1938".

Effects of inflation

General effect

Restaurant increasing prices by $1.00 due to inflation

Inflation is the decrease in the purchasing power of a currency. That is, when the general level of prices rise, each monetary unit can buy fewer goods and services in aggregate. The effect of inflation differs on different sectors of the economy, with some sectors being adversely affected while others benefitting. For example, with inflation, those segments in society which own physical assets, such as property, stock etc., benefit from the price/value of their holdings going up, when those who seek to acquire them will need to pay more for them. Their ability to do so will depend on the degree to which their income is fixed. For example, increases in payments to workers and pensioners often lag behind inflation, and for some people income is fixed. Also, individuals or institutions with cash assets will experience a decline in the purchasing power of the cash. Increases in the price level (inflation) erode the real value of money (the functional currency) and other items with an underlying monetary nature.

Debtors who have debts with a fixed nominal rate of interest will see a reduction in the "real" interest rate as the inflation rate rises. The real interest on a loan is the nominal rate minus the inflation rate. The formula R = N-I approximates the correct answer as long as both the nominal interest rate and the inflation rate are small. The correct equation is r = n/i where r, n and i are expressed as ratios (e.g. 1.2 for +20%, 0.8 for −20%). As an example, when the inflation rate is 3%, a loan with a nominal interest rate of 5% would have a real interest rate of approximately 2% (in fact, it's 1.94%). Any unexpected increase in the inflation rate would decrease the real interest rate. Banks and other lenders adjust for this inflation risk either by including an inflation risk premium to fixed interest rate loans, or lending at an adjustable rate.

Negative

High or unpredictable inflation rates are regarded as harmful to an overall economy. They add inefficiencies in the market, and make it difficult for companies to budget or plan long-term. Inflation can act as a drag on productivity as companies are forced to shift resources away from products and services to focus on profit and losses from currency inflation. Uncertainty about the future purchasing power of money discourages investment and saving. Inflation hurts asset prices such as stock performance in the short-run, as it erodes non-energy corporates' profit margins and leads to central banks' policy tightening measures. Inflation can also impose hidden tax increases. For instance, inflated earnings push taxpayers into higher income tax rates unless the tax brackets are indexed to inflation.

With high inflation, purchasing power is redistributed from those on fixed nominal incomes, such as some pensioners whose pensions are not indexed to the price level, towards those with variable incomes whose earnings may better keep pace with the inflation. This redistribution of purchasing power will also occur between international trading partners. Where fixed exchange rates are imposed, higher inflation in one economy than another will cause the first economy's exports to become more expensive and affect the balance of trade. There can also be negative effects to trade from an increased instability in currency exchange prices caused by unpredictable inflation.

Hoarding
People buy durable and/or non-perishable commodities and other goods as stores of wealth, to avoid the losses expected from the declining purchasing power of money, creating shortages of the hoarded goods.
Social unrest and revolts
Inflation can lead to massive demonstrations and revolutions. For example, inflation and in particular food inflation is considered one of the main reasons that caused the 2010–11 Tunisian revolution and the 2011 Egyptian revolution, according to many observers including Robert Zoellick, president of the World Bank. Tunisian president Zine El Abidine Ben Ali was ousted, Egyptian President Hosni Mubarak was also ousted after only 18 days of demonstrations, and protests soon spread in many countries of North Africa and Middle East.
Hyperinflation
If inflation becomes too high, it can cause people to severely curtail their use of the currency, leading to an acceleration in the inflation rate. High and accelerating inflation grossly interferes with the normal workings of the economy, hurting its ability to supply goods. Hyperinflation can lead people to abandon the use of the country's currency in favour of external currencies (dollarization), as has been reported to have occurred in North Korea).
Allocative efficiency
A change in the supply or demand for a good will normally cause its relative price to change, signaling the buyers and sellers that they should re-allocate resources in response to the new market conditions. But when prices are constantly changing due to inflation, price changes due to genuine relative price signals are difficult to distinguish from price changes due to general inflation, so agents are slow to respond to them. The result is a loss of allocative efficiency.
Shoe leather cost
High inflation increases the opportunity cost of holding cash balances and can induce people to hold a greater portion of their assets in interest paying accounts. However, since cash is still needed to carry out transactions this means that more "trips to the bank" are necessary to make withdrawals, proverbially wearing out the "shoe leather" with each trip.
Menu costs
Low-cost price adjustment
With high inflation, firms must change their prices often to keep up with economy-wide changes. But often changing prices is itself a costly activity whether explicitly, as with the need to print new menus, or implicitly, as with the extra time and effort needed to change prices constantly.
Tax
Inflation serves as a hidden tax on currency holdings.

Positive

Labour-market adjustments
Nominal wages are slow to adjust downwards. This can lead to prolonged disequilibrium and high unemployment in the labor market. Since inflation allows real wages to fall even if nominal wages are kept constant, moderate inflation enables labor markets to reach equilibrium faster.
Room to maneuver
The primary tools for controlling the money supply are the ability to set the discount rate, the rate at which banks can borrow from the central bank, and open market operations, which are the central bank's interventions into the bonds market with the aim of affecting the nominal interest rate. If an economy finds itself in a recession with already low, or even zero, nominal interest rates, then the bank cannot cut these rates further (since negative nominal interest rates are impossible) to stimulate the economy – this situation is known as a liquidity trap.
Mundell–Tobin effect
According to the Mundell-Tobin effect, an increase in inflation leads to an increase in capital investment, which leads to an increase in growth. The Nobel laureate Robert Mundell noted that moderate inflation would induce savers to substitute lending for some money holding as a means to finance future spending. That substitution would cause market clearing real interest rates to fall. The lower real rate of interest would induce more borrowing to finance investment. In a similar vein, Nobel laureate James Tobin noted that such inflation would cause businesses to substitute investment in physical capital (plant, equipment, and inventories) for money balances in their asset portfolios. That substitution would mean choosing the making of investments with lower rates of real return. (The rates of return are lower because the investments with higher rates of return were already being made before.) The two related effects are known as the Mundell–Tobin effect. Unless the economy is already overinvesting according to models of economic growth theory, that extra investment resulting from the effect would be seen as positive.
Instability with deflation
Economist S.C. Tsiang noted that once substantial deflation is expected, two important effects will appear; both a result of money holding substituting for lending as a vehicle for saving. The first was that continually falling prices and the resulting incentive to hoard money will cause instability resulting from the likely increasing fear, while money hoards grow in value, that the value of those hoards are at risk, as people realize that a movement to trade those money hoards for real goods and assets will quickly drive those prices up. Any movement to spend those hoards "once started would become a tremendous avalanche, which could rampage for a long time before it would spend itself." Thus, a regime of long-term deflation is likely to be interrupted by periodic spikes of rapid inflation and consequent real economic disruptions. The second effect noted by Tsiang is that when savers have substituted money holding for lending on financial markets, the role of those markets in channeling savings into investment is undermined. With nominal interest rates driven to zero, or near zero, from the competition with a high return money asset, there would be no price mechanism in whatever is left of those markets. With financial markets effectively euthanized, the remaining goods and physical asset prices would move in perverse directions. For example, an increased desire to save could not push interest rates further down (and thereby stimulate investment) but would instead cause additional money hoarding, driving consumer prices further down and making investment in consumer goods production thereby less attractive. Moderate inflation, once its expectation is incorporated into nominal interest rates, would give those interest rates room to go both up and down in response to shifting investment opportunities, or savers' preferences, and thus allow financial markets to function in a more normal fashion.

Cost-of-living allowance

The real purchasing power of fixed payments is eroded by inflation unless they are inflation-adjusted to keep their real values constant. In many countries, employment contracts, pension benefits, and government entitlements (such as social security) are tied to a cost-of-living index, typically to the consumer price index. A cost-of-living adjustment (COLA) adjusts salaries based on changes in a cost-of-living index. It does not control inflation, but rather seeks to mitigate the consequences of inflation for those on fixed incomes. Salaries are typically adjusted annually in low inflation economies. During hyperinflation they are adjusted more often. They may also be tied to a cost-of-living index that varies by geographic location if the employee moves.

Annual escalation clauses in employment contracts can specify retroactive or future percentage increases in worker pay which are not tied to any index. These negotiated increases in pay are colloquially referred to as cost-of-living adjustments ("COLAs") or cost-of-living increases because of their similarity to increases tied to externally determined indexes.

Controlling inflation

The U.S. effective federal funds rate charted over fifty years

Monetary policy

Monetary policy is the policy enacted by the monetary authorities (most frequently the central bank of a nation) to control the interest rate – or equivalently the money supply – so as to control inflation and ensure price stability. Higher interest rates reduce the economy's money supply because fewer people seek loans. When banks make loans, the loan proceeds are generally deposited in bank accounts that are part of the money supply, thereby expanding it. When banks make fewer loans, the amount of bank deposits and hence the money supply decrease. For example, in the early 1980s, when the US federal funds rate exceeded 15%, the quantity of Federal Reserve dollars fell 8.1%, from US$8.6 trillion down to $7.9 trillion.

In the latter half of the 20th century, there was debate between Keynesians and monetarists about the appropriate instrument to use to control inflation. Monetarists emphasize a low and steady growth rate of the money supply, while Keynesians emphasize controlling aggregate demand, by reducing demand during economic expansions and increasing demand during recessions to keep inflation stable. Control of aggregate demand can be achieved by using either monetary policy or fiscal policy (increasing taxation or reducing government spending to reduce demand). Ever since the 1980s, most countries have primarily relied on monetary policy to control inflation. When inflation beyond an acceptable level takes place, the country's central bank increases the interest rate, which will tend to slow down economic growth and inflation. Some central banks have a symmetrical inflation target, while others only react when inflation rises above a certain threshold.

In the 21st century, most economists favor a low and steady rate of inflation. In most countries, central banks or other monetary authorities are tasked with keeping interest rates and prices stable, and inflation near a target rate. These inflation targets may be publicly disclosed or not. In most OECD countries, the inflation target is usually about 2% to 3% (in developing countries like Armenia, the inflation target is higher, at around 4%). Central banks target a low inflation rate because they believe that high inflation is economically costly because it would create uncertainty about differences in relative prices and about the inflation rate itself. A low positive inflation rate is targeted rather than a zero or negative one because the latter could cause or worsen recessions; low (as opposed to zero or negative) inflation reduces the severity of economic recessions by enabling the labor market to adjust more quickly in a downturn, and reduces the risk that a liquidity trap prevents monetary policy from stabilizing the economy.

Other methods

Fixed exchange rates

Under a fixed exchange rate currency regime, a country's currency is tied in value to another single currency or to a basket of other currencies (or sometimes to another measure of value, such as gold). A fixed exchange rate is usually used to stabilize the value of a currency, vis-a-vis the currency it is pegged to. It can also be used as a means to control inflation. However, as the value of the reference currency rises and falls, so does the currency pegged to it. This essentially means that the inflation rate in the fixed exchange rate country is determined by the inflation rate of the country the currency is pegged to. In addition, a fixed exchange rate prevents a government from using domestic monetary policy to achieve macroeconomic stability.

Under the Bretton Woods agreement, most countries around the world had currencies that were fixed to the U.S. dollar. This limited inflation in those countries, but also exposed them to the danger of speculative attacks. After the Bretton Woods agreement broke down in the early 1970s, countries gradually turned to floating exchange rates. However, in the later part of the 20th century, some countries reverted to a fixed exchange rate as part of an attempt to control inflation. This policy of using a fixed exchange rate to control inflation was used in many countries in South America in the later part of the 20th century (e.g. Argentina (1991–2002), Bolivia, Brazil, Chile, Pakistan, etc.).

Gold standard

Two 20 krona gold coins from the Scandinavian Monetary Union, a historical example of an international gold standard

The gold standard is a monetary system in which a region's common medium of exchange is paper notes (or other monetary token) that are normally freely convertible into pre-set, fixed quantities of gold. The standard specifies how the gold backing would be implemented, including the amount of specie per currency unit. The currency itself has no innate value, but is accepted by traders because it can be redeemed for the equivalent specie. A U.S. silver certificate, for example, could be redeemed for an actual piece of silver.

The gold standard was partially abandoned via the international adoption of the Bretton Woods system. Under this system all other major currencies were tied at fixed rates to the US dollar, which itself was tied by the US government to gold at the rate of US$35 per ounce. The Bretton Woods system broke down in 1971, causing most countries to switch to fiat money – money backed only by the laws of the country.

Under a gold standard, the long term rate of inflation (or deflation) would be determined by the growth rate of the supply of gold relative to total output. Critics argue that this will cause arbitrary fluctuations in the inflation rate, and that monetary policy would essentially be determined by gold mining.

Wage and price controls

Another method attempted in the past have been wage and price controls ("incomes policies"). Temporary price controls may be used as a complement to other policies to fight inflation; price controls may make disinflation faster, while reducing the need for unemployment to reduce inflation. If price controls are used during a recession, the kinds of distortions that price controls cause may be lessened. However, economists generally advise against the imposition of price controls.

Wage and price controls, in combination with rationing, have been used successfully in wartime environments. However, their use in other contexts is far more mixed. Notable failures of their use include the 1972 imposition of wage and price controls by Richard Nixon. More successful examples include the Prices and Incomes Accord in Australia and the Wassenaar Agreement in the Netherlands.

In general, wage and price controls are regarded as a temporary and exceptional measures, only effective when coupled with policies designed to reduce the underlying causes of inflation during the wage and price control regime, for example, winning the war being fought. They often have perverse effects, due to the distorted signals they send to the market. Artificially low prices often cause rationing and shortages and discourage future investment, resulting in yet further shortages. The usual economic analysis is that any product or service that is under-priced is overconsumed. For example, if the official price of bread is too low, there will be too little bread at official prices, and too little investment in bread making by the market to satisfy future needs, thereby exacerbating the problem in the long term.

Gresham's law

From Wikipedia, the free encyclopedia

In economics, Gresham's law is a monetary principle stating that "bad money drives out good". For example, if there are two forms of commodity money in circulation, which are accepted by law as having similar face value, the more valuable commodity will gradually disappear from circulation.

The law was named in 1860 by economist Henry Dunning Macleod after Sir Thomas Gresham (1519–1579), an English financier during the Tudor dynasty. Gresham had urged Queen Elizabeth to restore confidence in then-debased English currency. The concept was thoroughly defined in medieval Europe by Nicolaus Copernicus and known centuries earlier in classical Antiquity, the Middle East and China.

"Good money" and "bad money"

Under Gresham's Law, "good money" is money that shows little difference between its nominal value (the face value of the coin) and its commodity value (the value of the metal of which it is made, often precious metals, nickel, or copper).

The price spread between face value and commodity value when it is minted is called seigniorage. As some coins do not circulate, remaining in the possession of coin collectors, this can increase demand for coinage.

On the other hand, "bad money" is money that has a commodity value considerably lower than its face value and is in circulation along with good money, where both forms are required to be accepted at equal value as legal tender.

In Gresham's day, bad money included any coin that had been debased. Debasement was often done by the issuing body, where less than the officially specified amount of precious metal was contained in an issue of coinage, usually by alloying it with a base metal. The public could also debase coins, usually by clipping or scraping off small portions of the precious metal, also known as "stemming" (reeded edges on coins were intended to make clipping evident). Other examples of bad money include counterfeit coins made from base metal. Today virtually all circulating coins are made from base metals, known as fiat money. While virtually all contemporary coinage is composed solely of base metals, during certain contemporary, 21st century years in which copper values were relatively high, at least one common coin (the U.S. nickel) still maintained "good money" status (largely depending on market rates).

In the case of clipped, scraped, or counterfeit coins, the commodity value was reduced by fraud, as the face value remains at the previous higher level. On the other hand, with a coinage debased by a government issuer, the commodity value of the coinage was often reduced quite openly, while the face value of the debased coins was held at the higher level by legal tender laws.

The old saying "a bad penny always turns up" is a colloquial recognition of Gresham's Law.

Theory

The law states that any circulating currency consisting of both "good" and "bad" money (both forms required to be accepted at equal value under legal tender law) quickly becomes dominated by the "bad" money. This is because people spending money will hand over the "bad" coins rather than the "good" ones, keeping the "good" ones for themselves. Legal tender laws act as a form of price control. In such a case, the intrinsically less valuable money is preferred in exchange, because people prefer to save the intrinsically more valuable money.

If a customer purchases an item which costs five pence, and possesses several silver sixpence coins. Some of these coins are more debased, while others are less so – but legally, they are all mandated to be of equal value. The customer would prefer to retain the better coins, and so offers the shopkeeper the most debased one. In turn, the shopkeeper must give one penny in change, and has every reason to give the most debased penny. Thus, the coins that circulate in the transaction will tend to be of the most debased sort available to the parties.

A stack of twenty Walking Liberty half dollars (left), which contain 90% silver. In an example of Gresham's law, these coins were quickly hoarded by the public after the Coinage Act of 1965 debased half dollars to contain only 40% silver, and then were debased entirely in 1971 to base cupronickel (right).

If "good" coins have a face value below that of their metallic content, individuals may be motivated to melt them down and sell the metal for its higher intrinsic value, even if such destruction is illegal. The 1965 United States half-dollar coins contained 40% silver, in previous years these coins were 90% silver. With the release of the 1965 half-dollar, which was legally required to be accepted at the same value as the earlier 90% halves, the older 90% silver coinage quickly disappeared from circulation, while the newer debased coins remained in use. As the value of the dollar (Federal Reserve notes) continued to decline, resulting in the value of the silver content exceeding the face value of the coins, many of the older half dollars were melted down or removed from circulation and into private collections and hoards. Beginning in 1971, the U.S. government abandoned including any silver in half dollars, as the metal value of the 40% silver coins began to exceed their face value, which resulted in a repeat of the previous event, as the 40% silver coins also began to vanish from circulation and into coin hoards.

A similar situation occurred in 2007, in the United States with the rising price of copper, zinc, and nickel, which led the U.S. government to ban the melting or mass exportation of one-cent and five-cent coins.

In addition to being melted down for its bullion value, money that is considered to be "good" tends to leave an economy through international trade. International traders are not bound by legal tender laws as citizens of the issuing country are, so they will offer higher value for good coins than bad ones. The good coins may leave their country of origin to become part of international trade, escaping that country's legal tender laws and leaving the "bad" money behind. This occurred in Britain during the period of adoption of the gold standard - in 1717 Isaac Newton, then Master of the Mint, declared the gold guinea to be worth 21 silver shillings. This overvalued the gold guinea in Britain, making it "bad", and encouraged people to send "good" silver shillings abroad, where it could buy more gold than at home. This gold was then minted as currency, which bought silver shillings, which were sent abroad for gold, and so on. For a century hardly any silver coins were minted in Britain, and Britain moved onto a de facto gold standard.

History of the concept

Gresham was not the first to state the law which took his name. The phenomenon had been noted by Aristophanes in his play The Frogs, which dates from around the end of the 5th century BC. The referenced passage from The Frogs is as follows (usually dated at 405 BC):

It has often struck our notice that the course our city runs
Is the same towards men and money. She has true and worthy sons:
She has good and ancient silver, she has good and recent gold.
These are coins untouched with alloys; everywhere their fame is told;
Not all Hellas holds their equal, not all Barbary far and near.
Gold or silver, each well minted, tested each and ringing clear.
Yet, we never use them! Others always pass from hand to hand.
Sorry brass just struck last week and branded with a wretched brand.
So with men we know for upright, blameless lives and noble names.
Trained in music and palaestra, freemen's choirs and freemen's games,
These we spurn for men of brass...

According to Ben Tamari, the currency devaluation phenomenon was already recognized in ancient sources. He brings some examples which include the Machpela Cave transaction and the building of the Temple from the Bible and the Mishna in tractate Bava Metzia (Bava Metzia 4:1) from the Talmud.

In China, Yuan dynasty economic authors Yeh Shih and Yuan Hsieh (c. 1223) were aware of the same phenomenon.

Ibn Taimiyyah (1263–1328) described the phenomenon as follows:

If the ruler cancels the use of a certain coin and mints another kind of money for the people, he will spoil the riches (amwal) which they possess, by decreasing their value as the old coins will now become merely a commodity. He will do injustice to them by depriving them of the higher values originally owned by them. Moreover, if the intrinsic values of coins are different it will become a source of profit for the wicked to collect the small (bad) coins and exchange them (for good money) and then they will take them to another country and shift the small (bad) money of that country (to this country). So (the value of) people's goods will be damaged.

Notably this passage mentions only the flight of good money abroad and says nothing of its disappearance due to hoarding or melting. Palestinian economist Adel Zagha also attributes a similar concept to medieval Islamic thinker Al-Maqrizi, who offered, claims Zagha, a close approximation to what would become known as Gresham's law centuries later.

In the 14th century it was noted by Nicole Oresme c. 1350, in his treatise On the Origin, Nature, Law, and Alterations of Money, and by jurist and historian Al-Maqrizi (1364–1442) in the Mamluk Empire.

Johannes de Strigys, an agent of Ludovico III Gonzaga, Marquis of Mantua in Venice, wrote in a June 1472 report che la cativa cazarà via la bona ("that the bad money will chase out the good").

In the year that Gresham was born, 1519, it was described by Nicolaus Copernicus in a treatise called Monetae cudendae ratio: "bad (debased) coinage drives good (un-debased) coinage out of circulation". Copernicus was aware of the practice of exchanging bad coins for good ones and melting down the latter or sending them abroad, and he seems to have drawn up some notes on this subject while he was at Olsztyn in 1519. He made them the basis of a report which he presented to the Prussian Diet held in 1522, attending the session with his friend Tiedemann Giese to represent his chapter. Copernicus's Monetae cudendae ratio was an enlarged, Latin version of that report, setting forth a general theory of money for the 1528 diet. He also formulated a version of the quantity theory of money. For this reason, it is occasionally known as the Gresham–Copernicus law.

Sir Thomas Gresham, a 16th century financial agent of the English Crown in the city of Antwerp, was one in a long series of proponents of the law, which he did to explain to Queen Elizabeth I what was happening to the English shilling. Her father, Henry VIII, had replaced 40% of the silver in the coin with base metals, to increase the government's income without raising taxes. Astute English merchants and ordinary subjects saved the good shillings from pure silver and circulated the bad ones. Hence, the bad money would be used whenever possible, and the good coinage would be saved and disappear from circulation.

According to the economist George Selgin in his paper "Gresham's Law":

As for Gresham himself, he observed "that good and bad coin cannot circulate together" in a letter written to Queen Elizabeth on the occasion of her accession in 1558. The statement was part of Gresham's explanation for the "unexampled state of badness" that England's coinage had been left in following the "Great Debasements" of Henry VIII and Edward VI, which reduced the metallic value of English silver coins to a small fraction of what it had been at the time of Henry VII. Owing to these debasements, Gresham observed to the Queen, that "all your fine gold was convayed out of this your realm".

Gresham made his observations of good and bad money while in the service of Queen Elizabeth, with respect only to the observed poor quality of British coinage. Earlier monarchs, Henry VIII and Edward VI, had forced the people to accept debased coinage by means of legal tender laws. Gresham also made his comparison of good and bad money where the precious metal in the money was the same metal, but of different weight. He did not compare silver to gold, or gold to paper.

In his "Gresham's Law" article, Selgin also offers the following comments regarding the origin of the name:

The expression "Gresham's Law" dates back only to 1858, when British economist Henry Dunning Macleod (1858, pp. 476–8) decided to name the tendency for bad money to drive good money out of circulation after Sir Thomas Gresham (1519–1579). However, references to such a tendency, sometimes accompanied by discussion of conditions promoting it, occur in various medieval writings, most notably Nicholas Oresme's (c. 1357) Treatise on money. The concept can be traced to ancient works, including Aristophanes' The Frogs, where the prevalence of bad politicians is attributed to forces similar to those favoring bad money over good.

Reverse of Gresham's law (Thiers' law)

The experiences of dollarization in countries with weak economies and currencies (such as Israel in the 1980s, Eastern Europe and countries in the period immediately after the collapse of the Soviet bloc, or Ecuador throughout the late 20th and early 21st century) may be seen as Gresham's law operating in its reverse form (Guidotti & Rodriguez, 1992) because in general, the dollar has not been legal tender in such situations, and in some cases, its use has been illegal.

Adam Fergusson and Costantino Bresciani-Turroni (in his book Le vicende del marco tedesco, published in 1931) pointed out that, during the great inflation in the Weimar Republic in 1923, as the official money became so worthless that virtually nobody would take it, people simply stopped accepting the currency in exchange for goods. That was particularly serious because farmers began to hoard food. Accordingly, any currency backed by any sort of value became a circulating medium of exchange. In 2009, hyperinflation in Zimbabwe began to show similar characteristics.

Those examples show that in the absence of effective legal tender laws, Gresham's Law works in reverse. If given the choice of what money to accept, people will accept the money they believe to be of highest long-term value, and not accept what they believe to be of low long-term value. If not given the choice and required to accept all money, good and bad, they will tend to keep the money of greater perceived value in their own possession, and pass the bad money to others.

In short, in the absence of legal tender laws, the seller will not accept anything but money of certain value (good money), but the existence of legal tender laws will cause the buyer to offer only money with the lowest commodity value (bad money), as the creditor must accept such money at face value.

Nobel Prize winner Robert Mundell believes that Gresham's Law could be more accurately rendered, taking care of the reverse, if it were expressed as: "Bad money drives out good if they exchange for the same price."

The reverse of Gresham's Law, that good money drives out bad money whenever the bad money becomes nearly worthless, has been named "Thiers' law" by economist Peter Bernholz in honor of French politician and historian Adolphe Thiers. "Thiers' Law will only operate later [in the inflation] when the increase of the new flexible exchange rate and of the rate of inflation lower the real demand for the inflating money."

Analogs in other fields

The principles of Gresham's law can sometimes be applied to different fields of study. Gresham's law may be generally applied to any circumstance in which the true value of something is markedly different from the value people are required to accept, due to factors such as lack of information or governmental decree.

Vice President Spiro Agnew used Gresham's law in describing American news media, stating that "Bad news drives out good news", although his argument was closer to that of a race to the bottom for higher ratings rather than over- and under-valuing certain kinds of news.

Gregory Bateson postulated an analogue to Gresham's law operating in cultural evolution, in which "the oversimplified ideas will always displace the sophisticated and the vulgar and hateful will always displace the beautiful. And yet the beautiful persists."

Cory Doctorow wrote that a similar effect to Gresham's law occurred in carbon offset trading. The alleged information asymmetry is that people find it difficult to distinguish just how effective credits purchased are, but can easily tell the price. As a result, cheap credits that are ineffective can displace expensive but worthwhile carbon credits. The example given was The Nature Conservancy offering cheap, yet "meaningless", carbon credits by purchasing cheap land unlikely to be logged anyway, rather than expensive and valuable land at risk of logging.

In the market for used cars, lemon automobiles (analogous to bad currency) will drive out the good cars. The problem is one of asymmetry of information. Sellers have a strong financial incentive to pass all used cars off as good cars, especially lemons. This makes it difficult to buy a good car at a fair price, as the buyer risks overpaying for a lemon. The result is that buyers will only pay the fair price of a lemon, so at least they reduce the risk of overpaying. High-quality cars tend to be pushed out of the market, because there is no good way to establish that they really are worth more. Certified pre-owned programs are an attempt to mitigate this problem by providing a warranty and other guarantees of quality. The Market for Lemons is a work that examines this problem in more detail.

Miracle

From Wikipedia, the free encyclopedia

A miracle is an event that is inexplicable by natural or scientific laws and accordingly gets attributed to some supernatural or praeternatural cause. Various religions often attribute a phenomenon characterized as miraculous to the actions of a supernatural being, (especially) a deity, a magician, a miracle worker, a saint, or a religious leader.

Informally, English-speakers often use the word miracle to characterise any beneficial event that is statistically unlikely but not contrary to the laws of nature, such as surviving a natural disaster, or simply a "wonderful" occurrence, regardless of likelihood (e.g. "the miracle of childbirth"). Some coincidences may be seen as miracles.

A true miracle would, by definition, be a non-natural phenomenon, leading many writers to dismiss miracles as physically impossible (that is, requiring violation of established laws of physics within their domain of validity) or impossible to confirm by their nature (because all possible physical mechanisms can never be ruled out). The former position is expressed (for instance) by Thomas Jefferson, and the latter by David Hume. Theologians typically say that, with divine providence, God regularly works through nature yet, as a creator, may work without, above, or against it as well.

Definitions

The word miracle is usually used to describe any beneficial event that is physically impossible or impossible to confirm by nature. Wayne Grudem defines a miracle as "a less common kind of God's activity in which he arouses people's awe and wonder and bears witness to himself." A deistic perspective of God's relation to the world defines a miracle as a direct intervention of God into the world.

Naturalistic explanations

A miracle may just be fake information or simply a fictional story, rather than something that truly happened. A miracle experience may be due to cognitive errors (e.g. overthinking, jumping to conclusions) or psychological errors (e.g. hallucinations) of witnesses. Use of some drugs such as psychedelics (e.g. ecstasy) may produce similar effects to religious experiences.

Law of truly large numbers

Statistically "impossible" events are often called miracles. For instance, when three classmates accidentally meet in a different country decades after having left school, they could consider this as "miraculous". However, a colossal number of events happen every moment on Earth; thus, extremely unlikely coincidences also happen every moment. Events that are considered "impossible" are therefore not impossible at all – they are just increasingly rare and dependent on the number of individual events. British mathematician J. E. Littlewood suggested that individuals should statistically expect one-in-a-million events ("miracles") to happen to them at the rate of about one per month. By his definition, seemingly miraculous events are actually commonplace.

Supernatural explanations

A miracle is a phenomenon not explained by known laws of nature. Criteria for classifying an event as a miracle vary. Often a religious text, such as the Bible or Quran, states that a miracle occurred, and believers may accept this as a fact.

Philosophical explanations

Aristotelian and Neo-Aristotelian

The Aristotelian view of God has God as pure actuality and considers him as the prime mover doing only what a perfect being can do, think. Jewish neo-Aristotelian philosophers, who are still influential today, include Maimonides, Samuel ben Judah ibn Tibbon, and Gersonides. Directly or indirectly, their views are still prevalent in much of the religious Jewish community.

Baruch Spinoza

In his Tractatus Theologico-Politicus Spinoza claims that miracles are merely lawlike events of whose causes we are ignorant. We should not treat them as having no cause or of having a cause immediately available. Rather the miracle is for combating the ignorance it entails, like a political project.

David Hume

According to the philosopher David Hume, a miracle is "a transgression of a law of nature by a particular volition of the Deity, or by the interposition of some invisible agent". The crux of his argument is this: "No testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact which it endeavours to establish." By Hume's definition, a miracle goes against our regular experience of how the universe works. As miracles are single events, the evidence for them is always limited and we experience them rarely. On the basis of experience and evidence, the probability that miracle occurred is always less than the probability that it did not occur. As it is rational to believe what is more probable, we are not supposed to have a good reason to believe that a miracle occurred.

Friedrich Schleiermacher

According to the Christian theologian Friedrich Schleiermacher "every event, even the most natural and usual, becomes a miracle as soon as the religious view of it can be the dominant".

Søren Kierkegaard

The philosopher Søren Kierkegaard, following Hume and Johann Georg Hamann, a Humean scholar, agrees with Hume's definition of a miracle as a transgression of a law of nature, but Kierkegaard, writing as his pseudonym Johannes Climacus, regards any historical reports to be less than certain, including historical reports of miracles, as all historical knowledge is always doubtful and open to approximation.

James Keller

James Keller states that "The claim that God has worked a miracle implies that God has singled out certain persons for some benefit which many others do not receive implies that God is unfair."

Religious views

According to a 2011 poll by the Pew Research Center, more than 90 percent of evangelical Christians believe miracles still take place. While Christians see God as sometimes intervening in human activities, Muslims see Allah as a direct cause of all events. "God’s overwhelming closeness makes it easy for Muslims to admit the miraculous in the world."

Buddhism

The Haedong Kosung-jon of Korea (Biographies of High Monks) records that King Beopheung of Silla had desired to promulgate Buddhism as the state religion. However, officials in his court opposed him. In the fourteenth year of his reign, Beopheung's "Grand Secretary", Ichadon, devised a strategy to overcome court opposition. Ichadon schemed with the king, convincing him to make a proclamation granting Buddhism official state sanction using the royal seal. Ichadon told the king to deny having made such a proclamation when the opposing officials received it and demanded an explanation. Instead, Ichadon would confess and accept the punishment of execution, for what would quickly be seen as a forgery. Ichadon prophesied to the king that at his execution a wonderful miracle would convince the opposing court faction of Buddhism's power. Ichadon's scheme went as planned, and the opposing officials took the bait. When Ichadon was executed on the 15th day of the 9th month in 527, his prophecy was fulfilled; the earth shook, the sun was darkened, beautiful flowers rained from the sky, his severed head flew to the sacred Geumgang mountains, and milk instead of blood sprayed 100 feet in the air from his beheaded corpse. The omen was accepted by the opposing court officials as a manifestation of heaven's approval, and Buddhism was made the state religion in 527 CE.

The Honchō Hokke Reigenki (c. 1040) of Japan contains a collection of Buddhist miracle stories.

Miracles play an important role in the veneration of Buddhist relics in Southern Asia. Thus, Somawathie Stupa in Sri Lanka is an increasingly popular site of pilgrimage and tourist destination thanks to multiple reports about miraculous rays of light, apparitions and modern legends, which often have been fixed in photographs and movies.

Christianity

The Miracle of the Slave, a 1548 painting by Tintoretto, from the Gallerie dell'Accademia in Venice. It portrays an episode of the life of Saint Mark, patron saint of Venice, taken from Jacobus de Voragine's Golden Legend. The scene shows a saint intervening to make a slave who is about to be martyred invulnerable.

The gospels record three sorts of miracles performed by Jesus: exorcisms, cures, and nature wonders. In the Gospel of John, the miracles are referred to as "signs" and the emphasis is on God demonstrating his underlying normal activity in remarkable ways. In the New Testament, the greatest miracle is the resurrection of Jesus, the event central to Christian faith.

Jesus explains in the New Testament that miracles are performed by faith in God. "If you have faith as small as a mustard seed, you can say to this mountain, 'move from here to there' and it will move." (Gospel of Matthew 17:20). After Jesus returned to heaven, the Book of Acts records the disciples of Jesus praying to God to grant that miracles be done in his name for the purpose of convincing onlookers that he is alive. (Acts 4:29–31).

Other passages mention false prophets who will be able to perform miracles to deceive "if possible, even the elect of Christ" (Matthew 24:24). 2 Thessalonians 2:9 says, "And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of His mouth, and shall destroy with the brightness of His coming: Even him, whose coming is after the working of Satan with all power and signs and lying wonders, and with all deceivableness of unrighteousness in them that perish; because they received not the love of the Truth, that they might be saved." Revelation 13:13,14 says, "And he doeth great wonders, so that he maketh fire come down from heaven on the earth in the sight of men, and deceiveth them that dwell on the earth by the means of those miracles which he had power to do in the sight of the beast; saying to them that dwell on the earth, that they should make an image to the beast, which had the wound by a sword, and did live." Revelation 16:14 says, "For they are the spirits of devils, working miracles, which go forth unto the kings of the earth and of the whole world, to gather them to the battle of that great day of God Almighty." Revelation 19:20 says, "And the beast was taken, and with him the false prophet that wrought miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone." These passages indicate that signs, wonders, and miracles are not necessarily committed by God. These miracles not committed by God are labeled as false(pseudo) miracles though which could mean that they are deceptive in nature and are not the same as the true miracles committed by God.

In early Christianity miracles were the most often attested motivations for conversions of pagans; pagan Romans took the existence of miracles for granted; Christian texts reporting them offered miracles as divine proof of the Christian God's unique claim to authority, relegating all other gods to the lower status of daimones: "of all worships, the Christian best and most particularly advertised its miracles by driving out of spirits and laying on of hands". The Gospel of John is structured around miraculous "signs": The success of the Apostles according to the church historian Eusebius of Caesarea lay in their miracles: "though laymen in their language", he asserted, "they drew courage from divine, miraculous powers". The conversion of Constantine by a miraculous sign in heaven is a prominent fourth-century example.

Since the Age of Enlightenment, miracles have often needed to be rationalized: C.S. Lewis, Norman Geisler, William Lane Craig, and other 20th-century Christians have argued that miracles are reasonable and plausible. For example, Lewis said that a miracle is something that comes totally out of the blue. If for thousands of years a woman can become pregnant only by sexual intercourse with a man, then if she were to become pregnant without a man, it would be a miracle.

There have been numerous claims of miracles by people of most Christian denominations, including but not limited to faith healings and casting out demons. Miracle reports are especially prevalent in Roman Catholicism and Pentecostal or Charismatic churches.

Catholic Church

The Catholic Church believes miracles are works of God, either directly, or through the prayers and intercessions of a specific saint or saints. There is usually a specific purpose connected to a miracle, e.g. the conversion of a person or persons to the Catholic faith or the construction of a church desired by God. The church says that it tries to be very cautious to approve the validity of putative miracles. The Catholic Church also says that it maintains particularly stringent requirements in validating the miracle's authenticity. The process is overseen by the Congregation for the Causes of Saints.

The Catholic Church has listed several events as miracles, some of them occurring in modern times. Before a person can be accepted as a saint, they must be posthumously confirmed to have performed two miracles. In the procedure of beatification of Pope John Paul II, who died in 2005, the Vatican announced on 14 January 2011 that Pope Benedict XVI had confirmed that the recovery of Marie Simon-Pierre from Parkinson's disease was a miracle.

Among the more notable miracles approved by the church are several Eucharistic miracles wherein the sacramental bread and wine are transformed into Christ's flesh and blood, such as the Miracle of Lanciano and cures in Lourdes.

According to 17th century documents, a young Spanish man's leg was miraculously restored to him in 1640 after having been amputated two and a half years earlier.

Another miracle approved by the church is the Miracle of the Sun, which is said to have occurred near Fátima, Portugal on October 13, 1917. According to legend, between 70,000 and 100,000 people, who were gathered at a cove near Fátima, witnessed the sunlight dim and change colors, and the Sun spin, dance about in the sky, and appear to plummet towards Earth, radiating great heat in the process. After the ten-minute event, the ground and the people's clothing, which had been drenched by a previous rainstorm, were both dry.

Velankanni (Mary) can be traced to the mid-16th century and is attributed to three miracles: the apparition of Mary and the Christ Child to a slumbering shepherd boy, the curing of a lame buttermilk vendor, and the rescue of Portuguese sailors from a violent sea storm.

In addition to these, the Catholic Church attributes miraculous causes to many otherwise inexplicable phenomena on a case-by-case basis. Only after all other possible explanations have been asserted to be inadequate will the church assume divine intervention and declare the miracle worthy of veneration by their followers. The church does not, however, enjoin belief in any extra-Scriptural miracle as an article of faith or as necessary for salvation.

Thomas Aquinas, a prominent Doctor of the Church, divided miracles into three types in his Summa contra Gentiles:

Things that are at times divinely accomplished, apart from the generally established order in things, are customarily called miracles; for we admire with some astonishment a certain event when we observe the effect but do not know its cause. And since one and the same cause is at times known to some people and unknown to others, the result is that of several who see an effect at the same time, some are moved to admiring astonishment, while others are not. For instance, the astronomer is not astonished when he sees an eclipse of the sun, for he knows its cause, but the person who is ignorant of this science must be amazed, for he ignores the cause. And so, a certain event is wondrous to one person, but not so to another. So, a thing that has a completely hidden cause is wondrous in an unqualified way, and this the name, miracle, suggests; namely, what is of itself filled with admirable wonder, not simply in relation to one person or another. Now, absolutely speaking, the cause hidden from every man is God. In fact, we proved above that no man in the present state of life can grasp His essence intellectually. Therefore, those things must properly be called miraculous which are done by divine power apart from the order generally followed in things.

Now, there are various degrees and orders of these miracles. Indeed, the highest rank among miracles is held by those events in which something is done by God which nature never could do. For example, that two bodies should be coincident; that the sun reverse its course, or stand still; that the sea open up and offer a way through which people may pass. And even among these an order may be observed. For the greater the things that God does are, and the more they are removed from the capacity of nature, the greater the miracle is. Thus, it is more miraculous for the sun to reverse its course than for the sea to be divided.

Then, the second degree among miracles is held by those events in which God does something which nature can do, but not in this order. It is a work of nature for an animal to live, to see, and to walk; but for it to live after death, to see after becoming blind, to walk after paralysis of the limbs, this nature cannot do—but God at times does such works miraculously. Even among this degree of miracles a gradation is evident, according as what is done is more removed from the capacity of nature.

Now, the third degree of miracles occurs when God does what is usually done by the working of nature, but without the operation of the principles of nature. For example, a person may be cured by divine power from a fever which could be cured naturally, and it may rain independently of the working of the principles of nature.

Evangelicalism

For a majority of Evangelical Christians, biblicism ensures that the miracles described in the Bible are still relevant and may be present in the life of the believer. Healings, academic or professional successes, the birth of a child after several attempts, the end of an addiction, etc., would be tangible examples of God's intervention with the faith and prayer, by the Holy Spirit. In the 1980s, the neo-charismatic movement re-emphasized miracles and faith healing. In certain churches, a special place is thus reserved for faith healings with laying on of hands during worship services or for campaigns evangelization. Faith healing or divine healing is considered to be an inheritance of Jesus acquired by his death and resurrection.

Hinduism

In Hinduism, miracles are focused on episodes of liberation of the spirit. A key example is the revelation of Krishna to Arjuna, wherein Krishna persuades Arjuna to rejoin the battle against his cousins by briefly and miraculously giving Arjuna the power to see the true scope of the Universe, and its sustainment within Krishna, which requires divine vision. This is a typical situation in Hindu mythology wherein "wondrous acts are performed for the purpose of bringing spiritual liberation to those who witness or read about them."

Hindu sages have criticized both expectation and reliance on miracles as cheats, situations where people have sought to earn a benefit without doing the work necessary to merit it. Miracles continue to be occasionally reported in the practice of Hinduism, with an example of a miracle modernly reported in Hinduism being the Hindu milk miracle of September 1995, with additional occurrences in 2006 and 2010, wherein statues of certain Hindu deities were seen to drink milk offered to them. The scientific explanation for the incident, attested by Indian academics, was that the material was wicked from the offering bowls by capillary action.

Islam

In the Quran, a miracle can be defined as a supernatural intervention in the life of human beings. According to this definition, miracles are present "in a threefold sense: in sacred history, in connection with Muhammad himself and in relation to revelation". The Quran does not use the technical Arabic word for miracle (Muʿd̲j̲iza) literally meaning "that by means of which [the Prophet] confounds, overwhelms, his opponents". It rather uses the term 'Ayah' (literally meaning sign). The term Ayah is used in the Quran in the above-mentioned threefold sense: it refers to the "verses" of the Quran (believed to be the divine speech in human language; presented by Muhammad as his chief miracle); as well as to miracles of it and the signs (particularly those of creation).

To defend the possibility of miracles and God's omnipotence against the encroachment of the independent secondary causes, some medieval Muslim theologians such as Al-Ghazali rejected the idea of cause and effect in essence, but accepted it as something that facilitates humankind's investigation and comprehension of natural processes. They argued that the nature was composed of uniform atoms that were "re-created" at every instant by God. Thus, if the soil was to fall, God would have to create and re-create the accident of heaviness for as long as the soil was to fall. For Muslim theologians, the laws of nature were only the customary sequence of apparent causes: customs of God.

Sufi biographical literature records claims of miraculous accounts of men and women. The miraculous prowess of the Sufi holy men includes firasa (clairvoyance), the ability to disappear from sight, to become completely invisible and practice buruz (exteriorization). The holy men reportedly tame wild beasts and traverse long distances in a very short time span. They could also produce food and rain in seasons of drought, heal the sick and help barren women conceive.

Judaism

Descriptions of miracles (Hebrew Ness, נס) appear in the Tanakh. Examples include prophets, such as Elijah who performed miracles like the raising of a widow's dead son (1 Kings 17:17–24) and Elisha whose miracles include multiplying the poor widow's jar of oil (2 Kings 4:1–7) and restoring to life the son of the woman of Shunem (2 Kings 4:18–37). The Torah describes many miracles related to Moses during his time as a prophet and the Exodus of the Israelites. Parting the Red Sea, and facilitating the Plagues of Egypt are among the most famous.

During the first century BCE, a variety of religious movements and splinter groups developed amongst the Jews in Judea. A number of individuals claimed to be miracle workers in the tradition of Moses, Elijah, and Elisha, the Jewish prophets. The Talmud provides some examples of such Jewish miracle workers, one of whom is Honi HaM'agel, who was famous for his ability to successfully pray for rain.

There are people who obscure all miracles by explaining them in terms of the laws of nature. When these heretics who do not believe in miracles disappear and faith increases in the world, then the Mashiach will come. For the essence of the Redemption primarily depends on this – that is, on faith.

Most Chasidic communities are rife with tales of miracles that follow a yechidut, a spiritual audience with a tzadik: barren women become pregnant, cancer tumors shrink, wayward children become pious. Many Hasidim claim that miracles can take place in merit of partaking of the shirayim (the leftovers from the rebbe's meal), such as miraculous healing or blessings of wealth or piety.

Criticism

Thomas Paine, one of the Founding Fathers of the American Revolution, wrote "All the tales of miracles, with which the Old and New Testament are filled, are fit only for impostors to preach and fools to believe."

Thomas Jefferson, principal author of the Declaration of Independence of the United States, edited a version of the Bible in which he removed sections of the New Testament containing supernatural aspects as well as perceived misinterpretations he believed had been added by the Four Evangelists. Jefferson wrote, "The establishment of the innocent and genuine character of this benevolent moralist, and the rescuing it from the imputation of imposture, which has resulted from artificial systems, [footnote: e.g. The immaculate conception of Jesus, his deification, the creation of the world by him, his miraculous powers, his resurrection and visible ascension, his corporeal presence in the Eucharist, the Trinity; original sin, atonement, regeneration, election, orders of Hierarchy, etc. —T.J.] invented by ultra-Christian sects, unauthorized by a single word ever uttered by him, is a most desirable object, and one to which Priestley has successfully devoted his labors and learning."

American Revolutionary War patriot Ethan Allen wrote, "In those parts of the world where learning and science have prevailed, miracles have ceased; but in those parts of it as are barbarous and ignorant, miracles are still in vogue."

Robert Ingersoll wrote, "Not 20 people were convinced by the reported miracles of Christ, and yet people of the nineteenth century were coolly asked to be convinced on hearsay by miracles which those who are supposed to have seen them refused to credit."

Elbert Hubbard, American writer, publisher, artist, and philosopher, wrote "A miracle is an event described by those to whom it was told by people who did not see it."

Biologist Richard Dawkins has criticised the belief in miracles as a subversion of Occam's razor.

Mathematician Charles Hermite, in a discourse upon the world of mathematical truths and the physical world, stated that "The synthesis of the two is revealed partially in the marvellous correspondence between abstract mathematics on the one hand and all the branches of physics on the other".

Baden Powell, an English mathematician and Church of England priest, stated that if God is a lawgiver, then a "miracle" would break the lawful edicts that had been issued at Creation. Therefore, a belief in miracles would be entirely atheistic.

Black swan theory

From Wikipedia, the free encyclopedia
 
A black swan (Cygnus atratus) in Australia

The black swan theory or theory of black swan events is a metaphor that describes an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight. The term is based on an ancient saying that presumed black swans did not exist – a saying that became reinterpreted to teach a different lesson after they were discovered in Australia.

The theory was developed by Nassim Nicholas Taleb, starting in 2001, to explain:

  1. The disproportionate role of high-profile, hard-to-predict, and rare events that are beyond the realm of normal expectations in history, science, finance, and technology.
  2. The non-computability of the probability of consequential rare events using scientific methods (owing to the very nature of small probabilities).
  3. The psychological biases that blind people, both individually and collectively, to uncertainty and the substantial role of rare events in historical affairs.

Taleb's "black swan theory" refers only to unexpected events of large magnitude and consequence and their dominant role in history. Such events, considered extreme outliers, collectively play vastly larger roles than regular occurrences. More technically, in the scientific monograph "Silent Risk", Taleb mathematically defines the black swan problem as "stemming from the use of degenerate metaprobability".

Background

The phrase "black swan" derives from a Latin expression; its oldest known occurrence is from the 2nd-century Roman poet Juvenal's characterization in his Satire VI of something being "rara avis in terris nigroque simillima cygno" ("a rare bird in the lands and very much like a black swan"). When the phrase was coined, the black swan was presumed not to exist. The importance of the metaphor lies in its analogy to the fragility of any system of thought. A set of conclusions is potentially undone once any of its fundamental postulates is disproved. In this case, the observation of a single black swan would be the undoing of the logic of any system of thought, as well as any reasoning that followed from that underlying logic.

Juvenal's phrase was a common expression in 16th century London as a statement of impossibility. The London expression derives from the Old World presumption that all swans must be white because all historical records of swans reported that they had white feathers. In that context, a black swan was impossible or at least nonexistent.

However, in 1697, Dutch explorers led by Willem de Vlamingh became the first Europeans to see black swans, in Western Australia. The term subsequently metamorphosed to connote the idea that a perceived impossibility might later be disproven. Taleb notes that in the 19th century, John Stuart Mill used the black swan logical fallacy as a new term to identify falsification.

Black swan events were discussed by Nassim Nicholas Taleb in his 2001 book Fooled By Randomness, which concerned financial events. His 2007 book The Black Swan extended the metaphor to events outside of financial markets. Taleb regards almost all major scientific discoveries, historical events, and artistic accomplishments as "black swans"—undirected and unpredicted. He gives the rise of the Internet, the personal computer, World War I, the dissolution of the Soviet Union, and the September 11, 2001 attacks as examples of black swan events.

Taleb asserts:

What we call here a Black Swan (and capitalize it) is an event with the following three attributes.

First, it is an outlier, as it lies outside the realm of regular expectations, because nothing in the past can convincingly point to its possibility. Second, it carries an extreme 'impact'. Third, in spite of its outlier status, human nature makes us concoct explanations for its occurrence after the fact, making it explainable and predictable.

I stop and summarize the triplet: rarity, extreme 'impact', and retrospective (though not prospective) predictability. A small number of Black Swans explains almost everything in our world, from the success of ideas and religions, to the dynamics of historical events, to elements of our own personal lives.

Identifying

Based on the author's criteria:

  1. The event is a surprise (to the observer).
  2. The event has a major effect.
  3. After the first recorded instance of the event, it is rationalized by hindsight, as if it could have been expected; that is, the relevant data were available but unaccounted for in risk mitigation programs. The same is true for the personal perception by individuals.

According to Taleb, as it was expected with great certainty that a global pandemic would eventually take place, the COVID-19 pandemic is not a black swan, but is considered to be a white swan; such an event has a major effect, but is compatible with statistical properties.

Coping with black swans

The practical aim of Taleb's book is not to attempt to predict events which are unpredictable, but to build robustness against negative events while still exploiting positive events. Taleb contends that banks and trading firms are very vulnerable to hazardous black swan events and are exposed to unpredictable losses. On the subject of business, and quantitative finance in particular, Taleb critiques the widespread use of the normal distribution model employed in financial engineering, calling it a Great Intellectual Fraud. Taleb elaborates the robustness concept as a central topic of his later book, Antifragile: Things That Gain From Disorder.

In the second edition of The Black Swan, Taleb provides "Ten Principles for a Black-Swan-Robust Society".

Taleb states that a black swan event depends on the observer. For example, what may be a Black Swan surprise for a turkey is not a Black Swan surprise to its butcher; hence the objective should be to "avoid being the turkey" by identifying areas of vulnerability in order to "turn the Black Swans white".

Epistemological approach

Taleb's black swan is different from the earlier philosophical versions of the problem, specifically in epistemology, as it concerns a phenomenon with specific empirical and statistical properties which he calls, "the fourth quadrant".

Taleb's problem is about epistemic limitations in some parts of the areas covered in decision making. These limitations are twofold: philosophical (mathematical) and empirical (human-known) epistemic biases. The philosophical problem is about the decrease in knowledge when it comes to rare events because these are not visible in past samples and therefore require a strong a priori (extrapolating) theory; accordingly, predictions of events depend more and more on theories when their probability is small. In the "fourth quadrant", knowledge is uncertain and consequences are large, requiring more robustness.

According to Taleb, thinkers who came before him who dealt with the notion of the improbable (such as Hume, Mill, and Popper) focused on the problem of induction in logic, specifically, that of drawing general conclusions from specific observations. The central and unique attribute of Taleb's black swan event is that it is high-profile. His claim is that almost all consequential events in history come from the unexpected – yet humans later convince themselves that these events are explainable in hindsight.

One problem, labeled the ludic fallacy by Taleb, is the belief that the unstructured randomness found in life resembles the structured randomness found in games. This stems from the assumption that the unexpected may be predicted by extrapolating from variations in statistics based on past observations, especially when these statistics are presumed to represent samples from a normal distribution. These concerns often are highly relevant in financial markets, where major players sometimes assume normal distributions when using value at risk models, although market returns typically have fat tail distributions.

Taleb said:

I don't particularly care about the usual. If you want to get an idea of a friend's temperament, ethics, and personal elegance, you need to look at him under the tests of severe circumstances, not under the regular rosy glow of daily life. Can you assess the danger a criminal poses by examining only what he does on an ordinary day? Can we understand health without considering wild diseases and epidemics? Indeed the normal is often irrelevant. Almost everything in social life is produced by rare but consequential shocks and jumps; all the while almost everything studied about social life focuses on the 'normal,' particularly with 'bell curve' methods of inference that tell you close to nothing. Why? Because the bell curve ignores large deviations, cannot handle them, yet makes us confident that we have tamed uncertainty. Its nickname in this book is GIF, Great Intellectual Fraud.

More generally, decision theory, which is based on a fixed universe or a model of possible outcomes, ignores and minimizes the effect of events that are "outside the model". For instance, a simple model of daily stock market returns may include extreme moves such as Black Monday (1987), but might not model the breakdown of markets following the September 11, 2001 attacks. Consequently, the New York Stock Exchange and Nasdaq exchange remained closed till September 17, 2001, the most protracted shutdown since the Great Depression. A fixed model considers the "known unknowns", but ignores the "unknown unknowns", made famous by a statement of Donald Rumsfeld. The term "unknown unknowns" appeared in a 1982 New Yorker article on the aerospace industry, which cites the example of metal fatigue, the cause of crashes in Comet airliners in the 1950s.

Deterministic chaotic dynamics reproducing the Black Swan Event have been researched in economics. That is in agreement with Taleb's comment regarding some distributions which are not usable with precision, but which are more descriptive, such as the fractal, power law, or scalable distributions and that awareness of these might help to temper expectations. Beyond this, Taleb emphasizes that many events simply are without precedent, undercutting the basis of this type of reasoning altogether.

Taleb also argues for the use of counterfactual reasoning when considering risk.

Lie group

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Lie_group In mathematics , a Lie gro...