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Tuesday, August 23, 2022

Tariffs in United States history

From Wikipedia, the free encyclopedia

Tariffs have historically served a key role in the trade policy of the United States. Their purpose was to generate revenue for the federal government and to allow for import substitution industrialization (industrialization of a nation by replacing foreign imports with domestic production) by acting as a protective barrier around infant industries. They also aimed to reduce the trade deficit and the pressure of foreign competition. Tariffs were one of the pillars of the American System that allowed the rapid development and industrialization of the United States. The United States pursued a protectionist policy from the beginning of the 19th century until the middle of the 20th century. Between 1861 and 1933, they had one of the highest average tariff rates on manufactured imports in the world. However American agricultural and industrial were cheaper than rival products and the tariff had an impact primarily on wool products. After 1942 the U.S. promoted worldwide free trade.

According to Dartmouth economist Douglas Irwin, tariffs have serve three primary purposes: "to raise revenue for the government, to restrict imports and protect domestic producers from foreign competition, and to reach reciprocity agreements that reduce trade barriers." From 1790 to 1860, average tariffs increased from 20 percent to 60 percent before declining again to 20 percent. From 1861 to 1933, which Irwin characterizes as the "restriction period", the average tariffs increased to 50 percent and remained at that level for several decades. From 1934 onwards, which Irwin characterizes as the "reciprocity period", the average tariff declined substantially until it leveled off at 5 percent.

Tariff revenues

Tariffs were the greatest (approaching 95% at times) source of federal revenue until the federal income tax began after 1913. For well over a century the federal government was largely financed by tariffs averaging about 20% on foreign imports. At the end of the American Civil War in 1865 about 63% of Federal income was generated by the excise taxes, which exceeded the 25.4% generated by tariffs. In 1915 during World War I tariffs generated only 30.1% of revenues. Since 1935 tariff income has continued to be a declining percentage of Federal tax income.

Historical trends

Federal taxes by type.pdf
Average tariff rates (France, UK, US)
 
Average Tariff Rates in US (1821–2016)
 
U.S. Trade Balance and Trade Policy (1895–2015)
 
Average Tariff Rates for Selected Countries (1913–2007)
 
Average Tariff Rates on manufactured products
 
Average Levels of Duties (1875 and 1913)
 

After the United States achieved independence in 1783, under the Articles of Confederation, the U.S. federal government, could not collect taxes directly but had to "request" money from each state—an almost fatal flaw for a federal government. Lack of ability to tax directly was one of several major flaws in the Articles of Confederation. The ability to tax directly was addressed in the drafting of the United States Constitution in May to September 1787 Constitutional Convention (United States) in Philadelphia. It came into effect in 1789. It specified that the United States House of Representatives has to originate all tax and tariff laws. The new government needed a way to collect taxes from all the states that were easy to enforce and had only a nominal cost to the average citizen. They had just finished a war on "Taxation without Representation". The Tariff of 1789 was the second bill signed by President George Washington imposing a tariff of about 5% on nearly all imports, with a few exceptions. In 1790 the United States Revenue Cutter Service was established to primarily enforce and collect the import tariffs. This service later became the United States Coast Guard.

Many American intellectuals and politicians during the country's catching-up period felt that the free trade theory advocated by British classical economists was not suited to their country. They argued that the country should develop manufacturing industries and use government protection and subsidies for this purpose, as Britain had done before them. Many of the great American economists of the time, until the last quarter of the 19th century, were strong advocates of industrial protection: Daniel Raymond who influenced Friedrich List, Mathew Carey and his son Henry, who was one of Lincoln's economic advisers. The intellectual leader of this movement was Alexander Hamilton, the first Secretary of the Treasury of the United States (1789-1795). Thus, it was against David Ricardo's theory of comparative advantage that the United States protected its industry. They pursued a protectionist policy from the beginning of the 19th century until the middle of the 20th century, after the Second World War.

In Report on Manufactures which is considered the first text to express modern protectionist theory, Alexander Hamilton argued that if a country wished to develop a new activity on its soil, it would have to temporarily protect it. According to him, this protection against foreign producers could take the form of import duties or, in rare cases, prohibition of imports. He called for customs barriers to allow American industrial development and to help protect infant industries, including bounties (subsidies) derived in part from those tariffs. He also believed that duties on raw materials should be generally low. Hamilton argued that despite an initial "increase of price" caused by regulations that control foreign competition, once a "domestic manufacture has attained to perfection… it invariably becomes cheaper".

Alexander Hamilton and Daniel Raymond were among the first theorists to present the infant industry argument. Hamilton was the first to use the term "infant industries" and to introduce it to the forefront of economic thinking. He believed that political independence was predicated upon economic independence. Increasing the domestic supply of manufactured goods, particularly war materials, was seen as an issue of national security. And he feared that Britain's policy towards the colonies would condemn the United States to be only producers of agricultural products and raw materials.

Britain initially did not want to industrialize the American colonies, and implemented policies to that effect (for example, banning high value-added manufacturing activities). Under British rule, America was denied the use of tariffs to protect its new industries. Thus, the American Revolution was, to some extent, a war against this policy, in which the commercial elite of the colonies rebelled against being forced to play a lesser role in the emerging Atlantic economy. This explains why, after independence, the Tariff Act of 1789 was the second bill of the Republic signed by President Washington allowing Congress to impose a fixed tariff of 5% on all imports, with a few exceptions

The Congress passed a tariff act (1789), imposing a 5% flat rate tariff on all imports. Between 1792 and the war with Britain in 1812, the average tariff level remained around 12.5%. In 1812 all tariffs were doubled to an average of 25% in order to cope with the increase in public expenditure due to the war. A significant shift in policy occurred in 1816, when a new law was introduced to keep the tariff level close to the wartime level—especially protected were cotton, woolen, and iron goods. The American industrial interests that had blossomed because of the tariff lobbied to keep it, and had it raised to 35 percent in 1816. The public approved, and by 1820, America's average tariff was up to 40 percent.

In the 19th century, statesmen such as Senator Henry Clay continued Hamilton's themes within the Whig Party under the name "American System which consisted of protecting industries and developing infrastructure in explicit opposition to the "British system" of free trade.

The American Civil War (1861-1865) was partially fought over the issue of tariffs. The agrarian interests of the South were opposed to any protection, while the manufacturing interests of the North wanted to maintain it. The fledgling Republican Party led by Abraham Lincoln, who called himself a "Henry Clay tariff Whig", strongly opposed free trade. Early in his political career, Lincoln was a member of the protectionist Whig Party and a supporter of Henry Clay. In 1847, he declared: "Give us a protective tariff, and we shall have the greatest nation on earth". He implemented a 44-percent tariff during the Civil War—in part to pay for railroad subsidies and for the war effort, and to protect favored industries. Tariffs remained at this level even after the war, thus the victory of the North in the Civil War ensured that the United States remained one of the greatest practitioners of tariff protection for industry.

From 1871 to 1913, "the average U.S. tariff on dutiable imports never fell below 38 percent [and] gross national product (GNP) grew 4.3 percent annually, twice the pace in free trade Britain and well above the U.S. average in the 20th century," notes Alfred Eckes Jr, chairman of the U.S. International Trade Commission under President Reagan.

In 1896, the GOP pledged platform pledged to "renew and emphasize our allegiance to the policy of protection, as the bulwark of American industrial independence, and the foundation of development and prosperity. This true American policy taxes foreign products and encourages home industry. It puts the burden of revenue on foreign goods; it secures the American market for the American producer. It upholds the American standard of wages for the American workingman".

In 1913, following the electoral victory of the Democrats in 1912, there was a significant reduction in the average tariff on manufactured goods from 44% to 25%. However, the First World War rendered this bill ineffective, and new "emergency" tariff legislation was introduced in 1922, after the Republicans returned to power in 1921.

According to Ha-Joon Chang, the United States, while being protectionist, was the fastest growing economy in the world throughout the 19th century and into the 1920s. It was only after the Second World War that the U.S. liberalized its trade (although not as unequivocally as Britain did in the mid-nineteenth century).

Colonial Era to 1789

In the colonial era, before 1775, nearly every colony levied its own tariffs, usually with lower rates for British products. There were taxes on ships (on a tonnage basis), import taxes on slaves, export taxes on tobacco, and import taxes on alcoholic beverages. The London government insisted on a policy of mercantilism whereby only British ships could trade in the colonies. In defiance, some American merchants engaged in smuggling.

During the Revolution, the British blockade from 1775 to 1783 largely ended foreign trade. In the 1783–89 Confederation Period, each state set up its own trade rules, often imposing tariffs or restrictions on neighboring states. The new Constitution, which went into effect in 1789, banned interstate tariffs or trade restrictions, as well as state taxes on exports.

Early National period, 1789–1828

The framers of the United States Constitution gave the federal government authority to tax, stating that Congress has the power to "... lay and collect taxes, duties, imposts and excises, pay the debts and provide for the common defense and general welfare of the United States." and also "To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes." Tariffs between states is prohibited by the U.S. Constitution, and all domestically made products can be imported or shipped to another state tax-free.

Responding to an urgent need for revenue and a trade imbalance with England that was fast destroying the infant American industries and draining the nation of its currency, the First United States Congress passed, and President George Washington signed, the Hamilton Tariff of 1789, which authorized the collection of duties on imported goods. Customs duties as set by tariff rates up to 1860 were usually about 80–95% of all federal revenue. Having just fought a war over taxation (among other things) the U.S. Congress wanted a reliable source of income that was relatively unobtrusive and easy to collect. It also sought to protect the infant industries that had developed during the war but which were now threatened by cheaper imports, especially from England. Tariffs and excise taxes were authorized by the United States Constitution and recommended by the first United States Secretary of the Treasury, Alexander Hamilton in 1789 to tax foreign imports and set up low excise taxes on whiskey and a few other products to provide the Federal Government with enough money to pay its operating expenses and to redeem at full value U.S. Federal debts and the debts the states had accumulated during the Revolutionary War. The Congress set low excise taxes on only a few goods, such as, whiskey, rum, tobacco, snuff and refined sugar. The tax on whiskey was highly controversial and set off massive protests by Western Farmers in the Whiskey Rebellion of 1794, which was suppressed by General Washington at the head of an army. The whiskey excise tax collected so little and was so despised it was abolished by President Thomas Jefferson in 1802.

All tariffs were on a long list of goods (dutiable goods) with different customs rates and some goods on a "free" list. Books and publications were nearly always on the free list. Congress spent enormous amounts of time figuring out these tariff import tax schedules.

With tariffs providing the basic federal revenue, an embargo on trade, or an enemy blockade, would threaten havoc. This happened in connection with the American economic warfare against Britain in the 1807–15 period. In 1807 imports dropped by more than half and some products became much more expensive or unobtainable. Congress passed the Embargo Act of 1807 and the Non-Intercourse Act (1809) to punish British and French governments for their actions; unfortunately their main effect was to reduce imports even more. The War of 1812 brought a similar set of problems as U.S. trade was again restricted by British naval blockades. The fiscal crisis was made much worse by the abolition of the First Bank of the U.S., which was the national bank. It was reestablished right after the war.

The lack of imported goods relatively quickly gave very strong incentives to start building several U.S. industries in the Northeast. Textiles and machinery manufacturing plants especially grew. Many new industries were set up and run profitably during the wars and about half of them failed after hostilities ceased and normal import competition resumed. Industry in the U.S. was advancing up the skill set, innovation knowledge and organization curve as they adapted to the Industrial Revolution's new machines and techniques.

The Tariff Act of 1789 imposed the first national source of revenue for the newly formed United States. The new U.S. Constitution ratified in 1789, allowed only the federal government to levy uniform tariffs. Only the federal government could set tariff rates (customs), so the old system of separate state rates disappeared. The new law taxed all imports at rates from 5 to 15 percent. These rates were primarily designed to generate revenue to pay the annual expenses of the federal government and the national debt and the debts the states had accumulated during the American War of Independence and to also promote manufactures and independence from foreign nations, especially for defense needs. Hamilton believed that all Revolutionary War debt should be paid in full to establish and keep U.S. financial credibility. In addition to income in his Report on Manufactures Treasury Secretary Alexander Hamilton proposed a far-reaching plan to use protective tariffs as a lever for rapid industrialization. In the late 18th century the industrial age was just starting and the United States had little or no textile industry—the heart of the early Industrial Revolution. The British government having just lost the Revolutionary War tried to maintain their near monopoly on cheap and efficient textile manufacturing by prohibiting the export of textile machines, machine models or the emigration of people familiar with these machines. Clothing in the early United States was nearly all hand made by a very time consuming and expensive process—just like it had been made for centuries before. The new textile manufacturing techniques in Britain were often over thirty times cheaper as well as being easier to use, more efficient and productive. Hamilton believed that a stiff tariff on imports would not only raise income but "protect" and help subsidize early efforts at setting up manufacturing facilities that could compete with British products.

Samuel Slater in 1789 emigrated (illegally since he was familiar with textile manufacturing) from Britain. Looking for opportunities he heard of the failing attempts at making cotton mills in Pawtucket, Rhode Island. Contacting the owners he promised to see if he could fix their mills—they offered him a full partnership if he succeeded. Declaring their early attempts unworkable he proceeded from January 1790 to December 1790 to build the first operational textile manufacturing facility in the United States. The Industrial Revolution was off and running in the United States. Initially the cost of their textiles was slightly higher than the cost of equivalent British goods but the tariff helped protect their early start-up industry.

Ashley notes that:

From 1790 onwards there were constant alterations in the tariff between 1792 and 1816 there were some twenty-five Tariff Acts passed, all modifying the customs duties in one way or another. But Hamilton's Report, and the ideas it embodied, do not seem to have exercised any special influence on the legislation of this period; the motives were always financial.

Higher tariffs were adopted during and after the War of 1812, when nationalists such as Henry Clay and John C. Calhoun saw the need for more federal income and more industry. In wartime, they declared, having a home industry was a necessity to avoid shortages. Likewise owners of the small new factories that were springing up in the northeast to mass-produce boots, hats, nails and other common items wanted higher tariffs that would significantly protect them when the more efficient British producers returned after the war ended. A 10% discount on the customs tax was offered on items imported in American ships, so that the American merchant marine would be supported.

Once industrialization and mass production started, the demand for higher and higher tariffs came from manufacturers and factory workers. They believed that their businesses should be protected from the lower wages and more efficient factories of Britain and the rest of Europe. Nearly every northern Congressman was eager to logroll a higher tariff rate for his local industry. Senator Daniel Webster, formerly a spokesperson for Boston's merchants who imported goods (and wanted low tariffs), switched dramatically to represent the manufacturing interests in the Tariff of 1824. Rates were especially high for bolts of cloth and for bar iron, of which Britain was a low-cost producer. The culmination came in the Tariff of 1828, ridiculed by free traders as the "Tariff of Abominations", with import custom duties averaging over 25 percent. Intense political opposition to higher tariffs came from Southern Democrats and plantation owners in South Carolina who had little manufacturing industry and imported some products with high tariffs. They would have to pay more for imports. They claimed their economic interest was being unfairly injured. They attempted to "nullify" the federal tariff and spoke of secession from the Union (see the Nullification Crisis). President Andrew Jackson let it be known he would use the U.S. Army to enforce the law, and no state supported the South Carolina call for nullification. A compromise ended the crisis included a lowering of the average tariff rate over ten years to a rate of 15% to 20%.

Second Party System, 1829–1859

The Democrats dominated the Second Party System and set low tariffs designed to pay for the government but not protect industry. Their opponents the Whigs wanted high protective tariffs but usually were outvoted in Congress. Tariffs soon became a major political issue as the Whigs (1832–1852) and (after 1854) the Republicans wanted to protect their mostly northern industries and constituents by voting for higher tariffs and the Southern Democrats, which had very little industry but imported many goods voted for lower tariffs. Each party as it came into power voted to raise or lower tariffs under the constraints that the Federal Government always needed a certain level of revenues. The United States public debt was paid off in 1834 and President Andrew Jackson, a strong Southern Democrat, oversaw the cutting of the tariff rates roughly in half and eliminating nearly all federal excise taxes in about 1835.

Henry Clay and his Whig Party, envisioning a rapid modernization based on highly productive factories, sought a high tariff. Their key argument was that startup factories, or "infant industries", would at first be less efficient than European (British) producers. Furthermore, American factory workers were paid higher wages than their European competitors. The arguments proved highly persuasive in industrial districts. Clay's position was adopted in the 1828 and 1832 Tariff Acts. The Nullification Crisis forced a partial abandonment of the Whig position. When the Whigs won victories in the 1840 and 1842 elections, taking control of Congress, they re-instituted higher tariffs with the Tariff of 1842. In examining these debates Moore finds that they were not precursors to Civil War. Instead they looked backward and continued the old debate whether foreign trade policy should embrace free trade or protectionism.

Walker Tariff

The Democrats won in 1845, electing James K. Polk as president. Polk succeeded in passing the Walker tariff of 1846 by uniting the rural and agricultural factions of the entire country for lower tariffs. They sought a level of a "tariff for revenue only" that would pay the cost of government but not show favoritism to one section or economic sector at the expense of another. The Walker Tariff actually increased trade with Britain and others and brought in more revenue to the federal treasury than the higher tariff. The average tariff on the Walker Tariff was about 25%. While protectionists in Pennsylvania and neighboring states were angered, the South achieved its goal of setting low tariff rates before the Civil War.

Low tariff of 1857

The Walker Tariff remained in place until 1857, when a nonpartisan coalition lowered them again with the Tariff of 1857 to 18%. This was in response to the British repeal of their protectionist "Corn Laws".

The Democrats in Congress, dominated by Southern Democrats, wrote and passed the tariff laws in the 1830s, 1840s, and 1850s, and kept reducing rates, so that the 1857 rates were down to about 15%, a move that boosted trade so overwhelmingly that revenues actually increased, from just over $20 million in 1840 ($0.5 billion in 2020 dollars), to more than $80 million by 1856 ($1.8 billion). The South had almost no complaints but the low rates angered many Northern industrialists and factory workers, especially in Pennsylvania, who demanded protection for their growing iron industry. The Republican Party replaced the Whigs in 1854 and also favored high tariffs to stimulate industrial growth; it was part of the 1860 Republican platform.

Third Party System

After the Second Party System ended in 1854 the Democrats lost control and the new Republican Party had its opportunity to raise rates. The Morrill Tariff significantly raising tariff rates became possible only after the Southern Senators walked out of Congress when their states left the Union, leaving a Republican majority. It was signed by Democratic President James Buchanan in early March 1861 shortly before President Abraham Lincoln took office. Pennsylvania iron mills and New England woolen mills mobilized businessmen and workers to call for high tariffs, but Republican merchants wanted low tariffs. The high tariff advocates lost in 1857, but stepped up their campaign by blaming the economic recession of 1857 on the lower rates. Economist Henry Charles Carey of Philadelphia was the most outspoken advocate, along with Horace Greeley and his influential newspaper, the New York Tribune. Increases were finally enacted in February 1861 after Southerners resigned their seats in Congress on the eve of the Civil War.

Some historians in recent decades have minimized the tariff issue as a cause of the war, noting that few people in 1860–61 said it was of central importance to them. Compromises were proposed in 1860–61 to save the Union, but they did not involve the tariff. Arguably, the effects of a tariff enacted in March 1861 could have made little effect upon any delegation which met prior to its signing. It is indicative of the Northern industrial supported and anti-agrarian position of the 1861 Republican-controlled congress. Some secessionist documents do mention a tariff issue, though not nearly as often as the preservation of the institution of slavery. However, a few libertarian economists place more importance on the tariff issue. The arguments that tariffs were a major cause of the Civil War have become a staple of the Lost Cause of the Confederacy.

1860–1912

Civil War

During the war far more revenue was needed, so the rates were raised again and again, along with many other taxes such as excise taxes on luxuries and income taxes on the rich. By far most of the wartime government revenue came from bonds and loans ($2.6 billion), not taxes ($357 million) or tariffs ($305 million).

The Morrill Tariff took effect a few weeks before the war began on April 12, 1861, and was not collected in the South. The Confederate States of America (CSA) passed its own tariff of about 15% on most items, including many items that previously were duty-free from the North. Previously tariffs between states were prohibited. The Confederates believed that they could finance their government by tariffs. The anticipated tariff revenue never appeared as the Union Navy blockaded their ports and the Union army restricted their trade with the Northern states. The Confederacy collected a mere $3.5 million in tariff revenue from the Civil War start to end and had to resort to inflation and confiscation instead for revenue.

Reconstruction era

Historian Howard K. Beale argued that high tariffs were needed during the Civil War, but were retained after the war for the benefit of Northern industrialists, who would otherwise lose markets and profits. To keep political control of Congress, Beale argued, Northern Industrialists worked through the Republican Party and supported Reconstruction policies that kept low-tariff Southern whites out of power. The Beale thesis was widely disseminated by the influential survey of Charles A. Beard, The Rise of American Civilization (1927).

In the late 1950s historians rejected the Beale–Beard thesis by showing that Northern businessmen were evenly divided on the tariff, and were not using Reconstruction policies to support it.

Politics of protection

The iron and steel industry, and the wool industry, were the well-organized interests groups that demanded (and usually obtained) high tariffs through support of the Republican Party. Industrial workers had much higher wages than their European counterparts, and they credited it to the tariff and voted Republican.

Democrats were divided on the issue, in large part because of pro-tariff elements in the Pennsylvania party who wanted to protect the growing iron industry, as well as pockets of high tariff support in nearby industrializing states. However President Grover Cleveland made low tariffs the centerpiece of Democratic Party policies in the late 1880s. His argument is that high tariffs were an unnecessary and unfair tax on consumers. The South and West generally supported low tariffs, and the industrial East high tariffs. Republican William McKinley was the outstanding spokesman for high tariffs, promising it would bring prosperity for all groups.

After the Civil War, high tariffs remained as the Republican Party remained in office and the Southern Democrats were restricted from office. Advocates insisted that tariffs brought prosperity to the nation as a whole and no one was really injured. As industrialization proceeded apace throughout the Northeast, some Democrats, especially Pennsylvanians, became high tariff advocates.

Farmers and wool

The Republican high-tariff advocates appealed to farmers with the theme that high-wage factory workers would pay premium prices for foodstuffs. This was the "home market" idea, and it won over most farmers in the Northeast, but it had little relevance to the southern and western farmers who exported most of their cotton, tobacco and wheat. In the late 1860s the wool manufacturers (based near Boston and Philadelphia) formed the first national lobby, and cut deals with wool-growing farmers in several states. Their challenge was that fastidious wool producers in Britain and Australia marketed a higher quality fleece than the Americans, and that British manufacturers had costs as low as the American mills. The result was a wool tariff that helped the farmers by a high tariff rate on imported wool—a tariff the American manufacturers had to pay—together with a high tariff on finished woolens and worsted goods.

U.S. industrial output

Apart from wool and woolens, American industry and agriculture—and industrial workers—had become the most efficient in the world in most industries by the 1880s as they took the lead in the Industrial Revolution. No other country had the industrial capacity, large market, high efficiency and low costs, or the complex distribution system needed to compete in most markets in the vast American market. Most imports were a few "luxury" goods. Indeed, it was the British who watched cheaper American products flooded their home islands. The London Daily Mail in 1900 complained:

We have lost to the American manufacturer electrical machinery, locomotives, steel rails, sugar-producing and agricultural machinery, and latterly even stationary engines, the pride and backbone of the British engineering industry.

Nevertheless, some American manufacturers and union workers demanded the high tariff be maintained. The tariff represented a complex balance of forces. Railroads, for example, consumed vast quantities of steel. To the extent tariffs raised steel prices, they paid much more making possible the U.S steel industry's massive investment to expand capacity and switch to the Bessemer process and later to the open hearth furnace. Between 1867 and 1900 U.S. steel production increased more than 500 times from 22,000 tons to 11,400,000 tons and Bessemer steel rails, first made in the U.S that would last 18 years under heavy traffic, would come to replace the old wrought iron rail that could only endure two years under light service. Taussig says that in 1881, British steel rails sold for $31 a ton, and if Americans imported them they paid a $28/ton tariff, giving $59/ton for an imported ton of rails. American mills charged $61/ton and made a good profit, which was then reinvested into increased capacity, higher quality steels, higher wages and benefits and more efficient production. By 1897 the American steel rail price had dropped to $19.60 per ton compared to the British price at $21.00—not including the $7.84 duty charge—demonstrating that the tariff had performed its purpose of giving the industry time to become competitive. Then the U.S. steel industry became an exporter of steel rail to England selling below the British price and during WW I would become the largest supplier of steel to the allies. From 1915 through 1918, the largest American steel company, U.S. Steel, alone delivered more steel each year than Germany and Austria-Hungary combined, totaling 99,700,000 tons during WW I. The Republicans became masters of negotiating exceedingly complex arrangements so that inside each of their congressional districts there were more satisfied "winners" than disgruntled "losers". The tariff after 1880 was an ideological relic with no longer any economic rationale.

Cleveland tariff policy

Democratic President Grover Cleveland redefined the issue in 1887, with his stunning attack on the tariff as inherently corrupt, opposed to true republicanism, and inefficient to boot: "When we consider that the theory of our institutions guarantees to every citizen the full enjoyment of all the fruits of his industry and enterprise... it is plain that the exaction of more than [minimal taxes] is indefensible extortion and a culpable betrayal of American fairness and justice." The election of 1888 was fought primarily over the tariff issue, and Cleveland lost. Republican Congressman William McKinley argued,

Free foreign trade gives our money, our manufactures, and our markets to other nations to the injury of our labor, our tradespeople, and our farmers. Protection keeps money, markets, and manufactures at home for the benefit of our own people.

Democrats campaigned energetically against the high McKinley tariff of 1890, and scored sweeping gains that year; they restored Cleveland to the White House in 1892. The severe depression that started in 1893 ripped apart the Democratic party. Cleveland and the pro-business Bourbon Democrats insisted on a much lower tariff. His problem was that Democratic electoral successes had brought in Democratic congressmen from industrial districts who were willing to raise rates to benefit their constituents. The Wilson–Gorman Tariff Act of 1894 did lower overall rates from 50 percent to 42 percent, but contained so many concessions to protectionism that Cleveland refused to sign it (it became law anyway).

McKinley tariff policy

President Teddy Roosevelt watches GOP team pull apart on tariff issue

McKinley campaigned heavily in 1896 on the high tariff as a positive solution to depression. Promising protection and prosperity to every economic sector, he won a smashing victory. The Republicans rushed through the Dingley tariff in 1897, boosting rates back to the 50 percent level. Democrats responded that the high rates created government sponsored "trusts" (monopolies) and led to higher consumer prices. McKinley won reelection by an even bigger landslide and started talking about a post-tariff era of reciprocal trade agreements. Reciprocity went nowhere; McKinley's vision was a half century too early. The Republicans split bitterly on the Payne–Aldrich Tariff of 1909. Republican President Theodore Roosevelt (1901–1909) saw the tariff issue was ripping his party apart, so he postponed any consideration of it. The delicate balance flew apart on under Republican William Howard Taft. He campaigned for president in 1908 for tariff "reform", which everyone assumed meant lower rates. The House lowered rates with the Payne Bill, then sent it to the Senate where Nelson Wilmarth Aldrich mobilized high-rate Senators. Aldrich was a New England businessman and a master of the complexities of the tariff, the Midwestern Republican insurgents were rhetoricians and lawyers who distrusted the special interests and assumed the tariff was "sheer robbery" at the expense of the ordinary consumer. Rural America believed that its superior morality deserved special protection, while the dastardly immorality of the trusts—and cities generally—merited financial punishment. Aldrich baited them. Did the insurgents want lower tariffs? His wickedly clever Payne–Aldrich Tariff Act of 1909 lowered the protection on Midwestern farm products, while raising rates favorable to his Northeast.

By 1913 with the new income tax generating revenue, the Democrats in Congress were able to reduce rates with the Underwood Tariff. The outbreak of war in 1914 made the impact of tariffs of much less importance compared to war contracts. When the Republicans returned to power they returned the rates to a high level in the Fordney–McCumber Tariff of 1922. The next raise came with the Smoot–Hawley Tariff Act of 1930 at the start of the Great Depression.

Tariff with Canada

The Canadian–American Reciprocity Treaty increased trade between 1855 and its ending in 1866. When it ended Canada turned to tariffs. The National Policy was a Canadian economic program introduced by John A. Macdonald's Conservative Party in 1879 after it returned to power. It had been an official policy, however, since 1876. It was based on high tariffs to protect Canada's manufacturing industry. Macdonald campaigned on the policy in the 1878 election, and handily beat the Liberal Party, which supported free trade.

Efforts to restore free trade with Canada collapsed when Canada rejected a proposed reciprocity treaty in fear of American imperialism in the 1911 federal election. Taft negotiated a reciprocity agreement with Canada, that had the effect of sharply lowering tariffs. Democrats supported the plan but Midwestern Republicans bitterly opposed it. Barnstorming the country for his agreement, Taft undiplomatically pointed to the inevitable integration of the North American economy, and suggested that Canada should come to a "parting of the ways" with Britain. Canada's Conservative Party, under the leadership of Robert Borden, now had an issue to regain power from the low-tariff Liberals; after a surge of pro-imperial anti-Americanism, the Conservatives won. Ottawa rejected reciprocity, reasserted the National Policy and went to London first for new financial and trade deals. The Payne Aldrich Tariff of 1909 actually changed little and had slight economic impact one way or the other, but the political impact was enormous. The insurgents felt tricked and defeated and swore vengeance against Wall Street and its minions Taft and Aldrich. The insurgency led to a fatal split down the middle in 1912 as the GOP lost its balance wheel.

1913 to present

Starting in the Civil War, protection was the ideological cement holding the Republican coalition together. High tariffs were used to promise higher sales to business, higher wages to industrial workers, and higher demand for their crops to farmers. Democrats said it was a tax on the little man. After 1900 Progressive insurgents said it promoted monopoly. It had greatest support in the Northeast, and greatest opposition in the South and West. The Midwest was the battle ground. The tariff issue was pulling the GOP apart. Roosevelt tried to postpone the issue, but Taft had to meet it head on in 1909 with the Payne–Aldrich Tariff Act. Eastern conservatives led by Nelson W. Aldrich wanted high tariffs on manufactured goods (especially woolens), while Midwesterners called for low tariffs. Aldrich outmaneuvered them by lowering the tariff on farm products, which outraged the farmers. The great battle over the high Payne–Aldrich Tariff Act in 1910 ripped the Republicans apart and set up the realignment in favor of the Democrats.

Woodrow Wilson made a drastic lowering of tariff rates a major priority for his presidency. The 1913 Underwood Tariff cut rates, but the coming of World War I in 1914 radically revised trade patterns. Reduced trade and, especially, the new revenues generated by the federal income tax made tariffs much less important in terms of economic impact and political rhetoric. The Wilson administration desired a 'revamping' of the current banking system, "... so that the banks may be the instruments, not the masters, of business and of individual enterprise and initiative.". President Wilson achieved this in the Federal Reserve Act of 1913. Working with the bullish Senator Aldrich and former presidential candidate William Jennings Bryan, he perfected a way to centralize the banking system to allow Congress to closely allocate paper money production. The Federal Reserve Act, with the Sixteenth Amendment of the Constitution, would create a trend of new forms of government funding. Ihe Democrats lowered the tariff in 1913 but the economic dislocations of the First World War made it irrelevant. When the Republicans returned to power in 1921 they again imposed a protective tariff. They raised it again with the Smoot–Hawley Tariff Act of 1930 to meet the Great Depression in the United States. But that made the depression worse. This time it backfired, as Canada, Britain, Germany, France and other industrial countries retaliated with their own tariffs and special, bilateral trade deals. American imports and exports both went into a tailspin. The Democrats promised an end to protection on a reciprocal country-by-country basis (which they did), hoping this would expand foreign trade (which it did not). By 1936 the tariff issue had faded from politics, and the revenue it raised was small. In World War II, both tariffs and reciprocity were insignificant compared to trade channeled through Lend-Lease. Low rates dominated the debate for the rest of the 20th century. In 2017 Donald Trump promised to use protective tariffs as a weapon to restore greatness to the economy.

Tariffs and the Great Depression

The years 1920 to 1929 are generally misdescribed as years in which protectionism increased in Europe. In fact, from a general point of view, the crisis was preceded in Europe by trade liberalisation. The weighted average of tariffs remained tendentially the same as in the years preceding the First World War: 24.6% in 1913, as against 24.9% in 1927. In 1928 and 1929, tariffs were lowered in almost all developed countries. In addition, the Smoot-Hawley Tariff Act was signed by Hoover on June 17, 1930, while the Wall Street crash took place in the fall of 1929. Most of the trade contraction occurred between January 1930 and July 1932, before most protectionist measures were introduced (except for the limited measures applied by the United States in the summer of 1930). In the view of Maurice Allais, it was therefore the collapse of international liquidity that caused the contraction of trade, not customs tariffs.

Milton Friedman also held the opinion that the Smoot–Hawley tariff of 1930 did not cause the Great Depression. Douglas A. Irwin writes : "most economists, both liberal and conservative, doubt that Smoot Hawley played much of a role in the subsequent contraction."

Peter Temin, explains a tariff is an expansionary policy, like a devaluation as it diverts demand from foreign to home producers. He notes that exports were 7 percent of GNP in 1929, they fell by 1.5 percent of 1929 GNP in the next two years and the fall was offset by the increase in domestic demand from tariff. He concludes that contrary the popular argument, contractionary effect of the tariff was small. (Temin, P. 1989. Lessons from the Great Depression, MIT Press, Cambridge, Mass)

William J. Bernstein wrote:

Between 1929 and 1932, real GDP fell 17 percent worldwide, and by 26 percent in the United States, but most economic historians now believe that only a minuscule part of that huge loss of both world GDP and the United States’ GDP can be ascribed to the tariff wars. .. At the time of Smoot-Hawley's passage, trade volume accounted for only about 9 percent of world economic output. Had all international trade been eliminated, and had no domestic use for the previously exported goods been found, world GDP would have fallen by the same amount — 9 percent. Between 1930 and 1933, worldwide trade volume fell off by one-third to one-half. Depending on how the falloff is measured, this computes to 3 to 5 percent of world GDP, and these losses were partially made up by more expensive domestic goods. Thus, the damage done could not possibly have exceeded 1 or 2 percent of world GDP — nowhere near the 17 percent falloff seen during the Great Depression... The inescapable conclusion: contrary to public perception, Smoot-Hawley did not cause, or even significantly deepen, the Great Depression.

Paul Krugman writes that protectionism does not lead to recessions. According to him, the decrease in imports (which can be obtained by the introduction of tariffs) has an expansionary effect, i.e. favourable to growth. Thus in a trade war, since exports and imports will decrease equally, for the whole world, the negative effect of a decrease in exports will be compensated by the expansionary effect of a decrease in imports. A trade war therefore does not cause a recession. Furthermore, he notes that the Smoot-Hawley tariff did not cause the Great Depression. The decline in trade between 1929 and 1933 "was almost entirely a consequence of the Depression, not a cause. Trade barriers were a response to the Depression, in part a consequence of deflation."

Trade liberalization

Tariffs up to the Smoot–Hawley Tariff Act of 1930, were set by Congress after many months of testimony and negotiations. In 1934, the U.S. Congress, in a rare delegation of authority, passed the Reciprocal Tariff Act of 1934, which authorized the executive branch to negotiate bilateral tariff reduction agreements with other countries. The prevailing view then was that trade liberalization may help stimulate economic growth. However, no one country was willing to liberalize unilaterally. Between 1934 and 1945, the executive branch negotiated over 32 bilateral trade liberalization agreements with other countries. The belief that low tariffs led to a more prosperous country are now the predominant belief with some exceptions. Multilateralism is embodied in the seven tariff reduction rounds that occurred between 1948 and 1994. In each of these "rounds", all General Agreement on Tariffs and Trade (GATT) members came together to negotiate mutually agreeable trade liberalization packages and reciprocal tariff rates. In the Uruguay round in 1994, the World Trade Organization (WTO) was established to help establish uniform tariff rates.

Currently only about 30% of all import goods are subject to tariffs in the United States, the rest are on the free list. The "average" tariffs now charged by the United States are at a historic low. The list of negotiated tariffs are listed on the Harmonized Tariff Schedule as put out by the United States International Trade Commission.

Post World War II

After the war the U.S. promoted the General Agreement on Tariffs and Trade (GATT) established in 1947, to minimize tariffs and other restrictions, and to liberalize trade among all capitalist countries. In 1995 GATT became the World Trade Organization (WTO); with the collapse of Communism its open markets/low tariff ideology became dominant worldwide in the 1990s.

American industry and labor prospered after World War II, but hard times set in after 1970. For the first time there was stiff competition from low-cost producers around the globe. Many rust belt industries faded or collapsed, especially the manufacture of steel, TV sets, shoes, toys, textiles and clothing. Toyota and Nissan threatened the giant domestic auto industry. In the late 1970s Detroit and the auto workers union combined to fight for protection. They obtained not high tariffs, but a voluntary restriction of imports from the Japanese government. Quotas were two-country diplomatic agreements that had the same protective effect as high tariffs, but did not invite retaliation from third countries. By limiting the number of Japanese automobiles that could be imported, quotas inadvertently helped Japanese companies push into larger, and more expensive market segments. The Japanese producers, limited by the number of cars they could export to America, opted to increase the value of their exports to maintain revenue growth. This action threatened the American producers' historical hold on the mid- and large-size car markets.

The Chicken tax was a 1964 response by President Lyndon B. Johnson to tariffs placed by Germany (then West Germany) on importation of US chicken. Beginning in 1962, during the President Kennedy administration, the US accused Europe of unfairly restricting imports of American poultry at the request of West German chicken farmers. Diplomacy failed, and in January 1964, two months after taking office, President Johnson retaliated by imposing a 25 percent tax on all imported light trucks. This directly affected the German built Volkswagen vans. Officially it was explained that the light trucks tax would offset the dollar amount of imports of Volkswagen vans from West Germany with the lost American sales of chickens to Europe. But audio tapes from the Johnson White House reveal that in January 1964, President Johnson was attempting to convince United Auto Workers's president Walter Reuther, not to initiate a strike just prior the 1964 election and to support the president's civil rights platform. Reuther in turn wanted Johnson to respond to Volkswagen's increased shipments to the United States.

1980s to present

China gained entry to the WTO as Most favoured nation in early 2000s.

During the Reagan and George H. W. Bush administrations Republicans abandoned protectionist policies, and came out against quotas and in favor of the GATT/WTO policy of minimal economic barriers to global trade. Free trade with Canada came about as a result of the Canada–U.S. Free Trade Agreement of 1987, which led in 1994 to the North American Free Trade Agreement (NAFTA). It was based on Reagan's plan to enlarge the scope of the market for American firms to include Canada and Mexico. President Bill Clinton, with strong Republican support in 1993, pushed NAFTA through Congress over the vehement objection of labor unions.

Likewise, in 2000 Clinton worked with Republicans to give China entry into WTO and "most favored nation" trading status (i.e., the same low tariffs promised to any other WTO member). NAFTA and WTO advocates promoted an optimistic vision of the future, with prosperity to be based on intellectuals skills and managerial know-how more than on routine hand labor. They promised that free trade meant lower prices for consumers. Opposition to liberalized trade came increasingly from labor unions, who argued that this system also meant lower wages and fewer jobs for American workers who could not compete against wages of less than a dollar an hour. The shrinking size and diminished political clout of these unions repeatedly left them on the losing side.

Despite overall decreases in international tariffs, some tariffs have been more resistant to change. For example, due partially to tariff pressure from the European Common Agricultural Policy, US agricultural subsidies have seen little decrease over the past few decades, even in the face of recent pressure from the WTO during the latest Doha talks.

On March 5, 2002, President George W. Bush placed tariffs on imported steel.

Deindustrialization

According to the Economic Policy Institute, free trade has created a large trade deficit in the United States for decades, leading to the closure of many factories and cost the United States millions of jobs in the manufacturing sector. Trade deficits replaces well-paying manufacturing jobs with low-wage service jobs. Moreover, trade deficits lead to significant wage losses, not only for workers in the manufacturing sector, but also for all workers throughout the economy who do not have a university degree. For example, in 2011, 100 million full-time, full-year workers without a university degree suffered an average loss of $1,800 on their annual salary.

Indeed, these workers who have lost their jobs in the manufacturing sector and who have to accept a reduction in their wages to find work in other sectors, are creating competition that reduces the wages of workers already employed in these other sectors. In addition, the threat of relocation of production facilities leads workers to accept wage cuts to keep their jobs.

According to the EPI, trade agreements have not reduced trade deficits but rather increased them. The growing trade deficit with China comes from China's manipulation of its currency, dumping policies, subsidies, trade barriers that give it a very important advantage in international trade. In addition, industrial jobs lost by imports from China are significantly better paid than jobs created by exports to China. So even if imports were equal to exports, workers would still lose out on their wages.

The manufacturing sector is a sector with very high productivity growth, which promotes high wages and good benefits for its workers. Indeed, this sector accounts for more than two thirds of private sector research and development and employs more than twice as many scientists and engineers as the rest of the economy. The manufacturing sector therefore provides a very important stimulus to overall economic growth. Manufacturing is also associated with well-paid service jobs such as accounting, business management, research and development and legal services. Deindustrialisation is therefore also leading to a significant loss of these service jobs. Deindustrialization thus means the disappearance of a very important driver of economic growth.

Smuggling and Coast Guard

Historically, high tariffs have led to high rates of smuggling. The United States Revenue Cutter Service was established by Secretary Hamilton in 1790 as an armed maritime law and custom enforcement service. Today it remains the primary maritime law enforcement force in the United States.

The U.S. Customs and Border Protection (CBP) is a federal law enforcement agency of the United States Department of Homeland Security charged with regulating and facilitating international trade, collecting customs (import duties or tariffs approved by the U.S. Congress), and enforcing U.S. regulations, including trade, customs and immigration. They man most border crossing stations and ports. When shipments of goods arrive at a border crossing or port, customs officers inspect the contents and charge a tax according to the tariff formula for that product. Usually the goods cannot continue on their way until the custom duty is paid. Custom duties are one of the easiest taxes to collect, and the cost of collection is small.

Tariffs and historical American politicians

In 1896, the GOP platform pledged to "renew and emphasize our allegiance to the policy of protection, as the bulwark of American industrial independence, and the foundation of development and prosperity. This true American policy taxes foreign products and encourages home industry. It puts the burden of revenue on foreign goods; it secures the American market for the American producer. It upholds the American standard of wages for the American workingman."

George Washington

"I use no porter or cheese in my family, but such as is made in America," the inaugural President George Washington wrote, boasting that these domestic products are "of an excellent quality." One of the first acts of Congress Washington signed was a tariff among whose stated purpose was "the encouragement and protection of manufactures." In his 1790 State of the Union Address, Washington justified his tariff policy for national security reasons:

A free people ought not only to be armed, but disciplined; to which end a uniform and well-digested plan is requisite; and their safety and interest require that they should promote such manufactories as tend to render them independent of others for essential, particularly military, supplies

Thomas Jefferson

As President Thomas Jefferson wrote in explaining why his views had evolved to favor more protectionist policies: "In so complicated a science as political economy, no one axiom can be laid down as wise and expedient for all times and circumstances, and for their contraries."

After the War of 1812, Jefferson's position began to resemble that of Washington, some level of protection was necessary to secure the nation's political independence. He said:

experience has taught me that manufactures are now as necessary to our independence as to our comfort: and if those who quote me as of a different opinion will keep pace with me in purchasing nothing foreign where an equivalent of domestic fabric can be obtained, without regard to difference of price

Henry Clay

In 1832, then the United States Senator from Kentucky, Henry Clay said about his disdain for "free traders" that "it is not free trade that they are recommending to our acceptance. It is in effect, the British colonial system that we are invited to adopt; and, if their policy prevail, it will lead substantially to the re-colonization of these States, under the commercial dominion of Great Britain." Clay said:

When gentlemen have succeeded in their design of an immediate or gradual destruction of the American System, what is their substitute? Free trade! Free trade! The call for free trade is as unavailing as the cry of a spoiled child, in its nurse's arms, for the moon, or the stars that glitter in the firmament of heaven. It never has existed; it never will exist. Trade implies, at least two parties. To be free, it should be fair, equal and reciprocal.

Clay explained that "equal and reciprocal" free trade "never has existed; [and] it never will exist." He warned against practicing "romantic trade philanthropy… which invokes us to continue to purchase the produce of foreign industry, without regard to the state or prosperity of our own." Clay that he was "utterly and irreconcilably opposed" to trade which would "throw wide open our ports to foreign productions" without reciprocation.

James Monroe

In 1822, President James Monroe observed that "whatever may be the abstract doctrine in favor of unrestricted commerce," the conditions necessary for its success—reciprocity and international peace—"has never occurred and can not be expected." Monroe said, "strong reasons… impose on us the obligation to cherish and sustain our manufactures."

Abraham Lincoln

President Abraham Lincoln declared, "Give us a protective tariff and we will have the greatest nation on earth." Lincoln warned that "the abandonment of the protective policy by the American Government… must produce want and ruin among our people."

Lincoln similarly said that, "if a duty amount to full protection be levied upon an article" that could be produced domestically, "at no distant day, in consequence of such duty," the domestic article "will be sold to our people cheaper than before."

Additionally, Lincoln argued that based on economies of scale, any temporary increase in costs resulting from a tariff would eventually decrease as the domestic manufacturer produced more. Lincoln did not see a tariff as a tax on low-income Americans because it would only burden the consumer according to the amount the consumer consumed. By the tariff system, the whole revenue is paid by the consumers of foreign goods... the burthen of revenue falls almost entirely on the wealthy and luxurious few, while the substantial and laboring many who live at home, and upon home products, go entirely free.

Lincoln argued that a tariff system was less intrusive than domestic taxation: The tariff is the cheaper system, because the duties, being collected in large parcels at a few commercial points, will require comparatively few officers in their collection; while by the direct tax system, the land must be literally covered with assessors and collectors, going forth like swarms of Egyptian locusts, devouring every blade of grass and other green thing.

William McKinley

President William McKinley stated the United States' stance under the Republican Party as:

Under free trade the trader is the master and the producer the slave. Protection is but the law of nature, the law of self-preservation, of self-development, of securing the highest and best destiny of the race of man. [It is said] that protection is immoral.... Why, if protection builds up and elevates 63,000,000 [the U.S. population] of people, the influence of those 63,000,000 of people elevates the rest of the world. We cannot take a step in the pathway of progress without benefiting mankind everywhere

[Free trade] destroys the dignity and independence of American labor... It will take away from the people of this country who work for a living—and the majority of them live by the sweat of their faces—it will take from them heart and home and hope. It will be self-destruction.

He also categorically rejected the "cheaper is better" argument:

They [free traders] say, 'Buy where you can buy the cheapest.' That is one of their maxims… Of course, that applies to labor as to everything else. Let me give you a maxim that is a thousand times better than that, and it is the protection maxim: 'Buy where you can pay the easiest.' And that spot of earth is where labor wins its highest rewards.

They say, if you had not the Protective Tariff things would be a little cheaper. Well, whether a thing is cheap or whether it is dear depends on what we can earn by our daily labor. Free trade cheapens the product by cheapening the producer. Protection cheapens the product by elevating the producer.

The protective tariff policy of the Republicans... has made the lives of the masses of our countrymen sweeter and brighter, and has entered the homes of America carrying comfort and cheer and courage. It gives a premium to human energy, and awakens the noblest aspiration in the breasts of men. Our own experience shows that it is the best for our citizenship and our civilization and that it opens up a higher and better destiny for our people.

Theodore Roosevelt

President Theodore Roosevelt believed that America's economic growth was due to the protective tariffs, which helped her industrialize. He acknowledged this in his State of the Union address from 1902:

The country has acquiesced in the wisdom of the protective-tariff principle. It is exceedingly undesirable that this system should be destroyed or that there should be violent and radical changes therein. Our past experience shows that great prosperity in this country has always come under a protective tariff.

Donald Trump

The Trump tariffs were imposed by executive order (not by act of Congress) during the presidency of Donald Trump as part of his economic policy. In January 2018, Trump imposed tariffs on solar panels and washing machines of 30 to 50 percent. He soon imposed tariffs on steel (25%) and aluminum (10%) from most countries. On June 1, 2018, this was extended on the European Union, Canada, and Mexico. Separately, on May 10, the Trump administration set a tariff of 25% on 818 categories of goods imported from China worth $50 billion. The only country which remained exempt from the steel and aluminum tariffs was Australia. Argentinian and Brazilian aluminium tariffs were started on December 2, 2019 in reaction to currency manipulation.

Weather front

From Wikipedia, the free encyclopedia
 
Approaching weather fronts are often visible from the ground, but are not always as well defined as this.

A weather front is a boundary separating air masses of several characteristics such as air density, wind, temperature and humidity. Disturbed and unstable weather often arises from these differences. For instance, cold fronts can bring bands of thunderstorms and cumulonimbus precipitation or be preceded by squall lines, while warm fronts are usually preceded by stratiform precipitation and fog. In summer, subtler humidity gradients known as dry lines can trigger severe weather. Some fronts produce no precipitation and little cloudiness, although there is invariably always a wind shift.

Cold fronts generally move from west to east, whereas warm fronts move poleward, although any direction is possible. Occluded fronts are a hybrid merge of the two, and stationary fronts are stalled in their motion. Cold fronts and cold occlusions move faster than warm fronts and warm occlusions, because the dense air behind them can lift as well as push the warmer air. Mountains and bodies of water can affect the movement and properties of fronts, other than atmospheric conditions. When the density contrast has diminished between the airmasses, for instance after flowing out over a uniformly warm ocean, the front can degenerate into a mere line which separates regions of differing wind velocity known as a shearline. This is most common over the open ocean.

Bergeron classification of air masses

The Bergeron classification is the most widely accepted form of air mass classification. Air mass classifications are indicated by three letters. The first letter describes its moisture properties, with c used for continental air masses (dry) and m for maritime air masses (moist). The second letter describes the thermal characteristic of its source region: T for tropical, P for polar, A for Arctic or Antarctic, M for monsoon, E for equatorial, and S for superior air (dry air formed by significant upward lift in the atmosphere). The third letter designates the stability of the atmosphere. If the air mass is colder than the ground below it, it is labeled k. If the air mass is warmer than the ground below it, it is labeled w.Fronts separate air masses of different types or origins, and are located along troughs of lower pressure.[5]

Different air masses which affect North America, as well as other continents, tend to be separated by frontal boundaries. In this illustration, the Arctic front separates Arctic from Polar air masses, while the Polar front separates Polar air from warm air masses. (cA is continental arctic; cP is continental polar; mP is maritime polar; cT is continental tropic; and mT is maritime tropic.)

Surface weather analysis

Weather map symbols:
1. cold front;
2. warm front;
3. stationary front;
4. occluded front;
5. surface trough;
6. squall/shear line;
7. dry line;
8. tropical wave;
9. trowal
 

A surface weather analysis is a special type of weather map which provides a top view of weather elements over a geographical area at a specified time based on information from ground-based weather stations. Weather maps are created by detecting, plotting and tracing the values of relevant quantities such as sea-level pressure, temperature, and cloud cover onto a geographical map to help find synoptic scale features such as weather fronts. Surface weather analyses have special symbols which show frontal systems, cloud cover, precipitation, or other important information. For example, an H may represent a high pressure area, implying fair or clear weather. An L on the other hand may represent low pressure, which frequently accompanies precipitation and storms. Low pressure also creates surface winds deriving from high pressure zones and vice versa. Various symbols are used not just for frontal zones and other surface boundaries on weather maps, but also to depict the present weather at various locations on the weather map. In addition, areas of precipitation help determine the frontal type and location.

Types

There are two different meanings used within meteorology to describe weather around a frontal zone. The term "anafront" describes boundaries which show instability, meaning air rises rapidly along and over the boundary to cause significant weather changes and heavy precipitation. A "katafront" is weaker, bringing smaller changes in temperature and moisture, as well as limited rainfall.

Cold front

A cold front is located along and on the bounds of the warm side of a tightly packed temperature gradient. On surface analysis charts, this temperature gradient is visible in isotherms and can sometimes also be identified using isobars since cold fronts often align with a surface trough. On weather maps, the surface position of the cold front is marked by a blue line with triangles pointing in the direction where cold air travels and it is placed at the leading edge of the cooler air mass. Cold fronts often bring rain, and sometimes heavy thunderstorms as well. Cold fronts can produce sharper and more intense changes in weather and move at a rate that is up to twice as fast as warm fronts, since cold air is more dense than warm air, lifting as well as pushing the warm air preceding the boundary. The lifting motion often creates a narrow line of showers and thunderstorms if enough humidity is present as the lifted moist warm air condenses. The concept of colder, dense air "wedging" under the less dense warmer air is too simplistic, as the upward motion is really part of a maintenance process for geostrophic balance on the rotating Earth in response to frontogenesis.

Warm front

Warm fronts are at the leading edge of a homogeneous advancing warm air mass, which is located on the equatorward edge of the gradient in isotherms, and lie within broader troughs of low pressure than cold fronts. A warm front moves more slowly than the cold front which usually follows because cold air is denser and harder to lift from the Earth's surface.

This also forces temperature differences across warm fronts to be broader in scale. Clouds appearing ahead of the warm front are mostly stratiform, and rainfall more gradually increases as the front approaches. Fog can also occur preceding a warm frontal passage. Clearing and warming is usually rapid after frontal passage. If the warm air mass is unstable, thunderstorms may be embedded among the stratiform clouds ahead of the front, and after frontal passage thundershowers may still continue. On weather maps, the surface location of a warm front is marked with a red line of semicircles pointing in the direction the airmass is travelling.

Occluded front

Occluded front depiction for the Northern Hemisphere

An occluded front is formed when a cold front overtakes a warm front, and usually forms around mature low-pressure areas, including cyclones. The cold and warm fronts curve naturally poleward into the point of occlusion, which is also known as the triple point. It lies within a sharp trough, but the air mass behind the boundary can be either warm or cold. In a cold occlusion, the air mass overtaking the warm front is cooler than the cold airmass receding from the warm front and plows under both air masses. In a warm occlusion, the cold air mass overtaking the warm front is warmer than the cold airmass receding from the warm front and rides over the colder air while lifting the warm air.

A wide variety of weather can be found along an occluded front, with thunderstorms possible, but usually their passage is also associated with a drying of the air mass. Within the occlusion of the front, a circulation of air brings warm air upward and sends drafts of cold air downward, or vice versa depending on the type of occlusion the front is experiencing. Precipitations and clouds are associated with the trowal, the projection on the Earth's surface of the tongue of warm air aloft formed during the occlusion process of the depression or storm.

Occluded fronts are indicated on a weather map by a purple line with alternating half-circles and triangles pointing in direction of travel. The trowal is indicated by a series of blue and red junction lines.

Warm sector

The warm sector is a near-surface air mass in between the warm front and the cold front, usually found on the equatorward side of an extratropical cyclone. With its warm and humid characteristics, this air is susceptive to convective instability and can sustain thunderstorms, especially if lifted by the advancing cold front.

Stationary front

A stationary front is a non-moving (or stalled) boundary between two air masses, neither of which is strong enough to replace the other. They tend to remain essentially in the same area for extended periods of time, especially with parallel winds directions; They usually move in waves but not persistently. There is normally a broad temperature gradient behind the boundary with more widely spaced isotherm packing.

A wide variety of weather can be found along a stationary front, but usually clouds and prolonged precipitation are found there. Stationary fronts either dissipate after several days or devolve into shear lines, but they can transform into a cold or warm front if the conditions aloft change. Stationary fronts are marked on weather maps with alternating red half-circles and blue spikes pointing opposite to each other, indicating no significant movement.

When stationary fronts become smaller in scale and stabilizes in temperature, degenerating to a narrow zone where wind direction changes significantly over a relatively short distance, they become known as shearlines. A shearline is depicted as a line of red dots and dashes. Stationary fronts may bring light snow or rain for a long period of time.

Dry line

A similar phenomenon to a weather front is the dry line, which is the boundary between air masses with significant moisture differences instead of temperature. When the westerlies increase on the north side of surface highs, areas of lowered pressure will form downwind of north–south oriented mountain chains, leading to the formation of a lee trough. Near the surface during daylight hours, warm moist air is denser than dry air of greater temperature, and thus the warm moist air wedges under the drier air like a cold front. At higher altitudes, the warm moist air is less dense than the cooler dry air and the boundary slope reverses. In the vicinity of the reversal aloft, severe weather is possible, especially when an occlusion or triple point is formed with a cold front. A weaker form of the dry line seen more commonly is the lee trough, which displays weaker differences in moisture. When moisture pools along the boundary during the warm season, it can be the focus of diurnal thunderstorms.

The dry line may occur anywhere on earth in regions intermediate between desert areas and warm seas. The southern plains west of the Mississippi River in the United States are a particularly favored location. The dry line normally moves eastward during the day and westward at night. A dry line is depicted on National Weather Service (NWS) surface analyses as an orange line with scallops facing into the moist sector. Dry lines are one of the few surface fronts where the pips indicated do not necessarily reflect the direction of motion.

Squall line

A shelf cloud such as this one can be a sign that a squall is imminent

Organized areas of thunderstorm activity not only reinforce pre-existing frontal zones, but can outrun actively existing cold fronts in a pattern where the upper level jet splits apart into two streams, with the resultant Mesoscale Convective System (MCS) forming at the point of the upper level split in the wind pattern running southeast into the warm sector parallel to low-level thickness lines. When the convection is strong and linear or curved, the MCS is called a squall line, with the feature placed at the leading edge of the significant wind shift and pressure rise. Even weaker and less organized areas of thunderstorms lead to locally cooler air and higher pressures, and outflow boundaries exist ahead of this type of activity, which can act as foci for additional thunderstorm activity later in the day.

These features are often depicted in the warm season across the United States on surface analyses and lie within surface troughs. If outflow boundaries or squall lines form over arid regions, a haboob may result. Squall lines are depicted on NWS surface analyses as an alternating pattern of two red dots and a dash labelled SQLN or SQUALL LINE, while outflow boundaries are depicted as troughs with a label of OUTFLOW BOUNDARY.

Precipitation produced

Convective precipitation

Fronts are the principal cause of significant weather. Convective precipitation (showers, thundershowers, heavy rain and related unstable weather) is caused by air being lifted and condensing into clouds by the movement of the cold front or cold occlusion under a mass of warmer, moist air. If the temperature differences of the two air masses involved are large and the turbulence is extreme because of wind shear and the presence of a strong jet stream, "roll clouds" and tornadoes may occur.

In the warm season, lee troughs, breezes, outflow boundaries and occlusions can lead to convection if enough moisture is available. Orographic precipitation is precipitation created through the lifting action of air due to airmasses moving over terrain such as mountains and hills, which is most common behind cold fronts that move into mountainous areas. It may sometimes occur in advance of warm fronts moving northward to the east of mountainous terrain. However, precipitation along warm fronts is relatively steady, as in light rain or drizzle. Fog, sometimes extensive and dense, often occurs in pre-warm-frontal areas. Although, not all fronts produce precipitation or even clouds because moisture must be present in the air mass which is being lifted.

Movement

Fronts are generally guided by winds aloft, but do not move as quickly. Cold fronts and occluded fronts in the Northern Hemisphere usually travel from the northwest to southeast, while warm fronts move more poleward with time. In the Northern Hemisphere a warm front moves from southwest to northeast. In the Southern Hemisphere, the reverse is true; a cold or occluded front usually moves from southwest to northeast, and a warm front moves from northwest to southeast. Movement is largely caused by the pressure gradient force (horizontal differences in atmospheric pressure) and the Coriolis effect, which is caused by Earth's spinning about its axis. Frontal zones can be slowed by geographic features like mountains and large bodies of warm water.

Equality (mathematics)

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