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Tuesday, July 10, 2018

Malnutrition

From Wikipedia, the free encyclopedia
 
Malnutrition
Synonyms Malnourishment
Orange ribbon.svg
An orange ribbon—the awareness ribbon for malnutrition.
Specialty Critical care medicine
Symptoms Problems with physical or mental development, poor energy levels, swollen legs and abdomen[1][2]
Causes Eating a diet in which nutrients are either not enough or are too much, malabsorption[3][4]
Risk factors Not breastfeed, gastroenteritis, pneumonia, malaria, measles[5]
Prevention Improving agricultural practices, reducing poverty, improving sanitation, empowerment of women[6][7]
Treatment Improved nutrition, supplementation, ready-to-use therapeutic foods, treating the underlying cause[6][8][9]
Frequency 815 million undernourished / 11% of the population (2017)[10]
Deaths 406,000 from nutritional deficiencies (2015)[11]

Malnutrition is a condition that results from eating a diet in which one or more nutrients are either not enough or are too much such that the diet causes health problems. It may involve calories, protein, carbohydrates, vitamins or minerals. Not enough nutrients is called undernutrition or undernourishment while too much is called overnutrition. Malnutrition is often used to specifically refer to undernutrition where an individual is not getting enough calories, protein, or micronutrients. If undernutrition occurs during pregnancy, or before two years of age, it may result in permanent problems with physical and mental development. Extreme undernourishment, known as starvation, may have symptoms that include: a short height, thin body, very poor energy levels, and swollen legs and abdomen. People also often get infections and are frequently cold. The symptoms of micronutrient deficiencies depend on the micronutrient that is lacking.

Undernourishment is most often due to not enough high-quality food being available to eat.[5] This is often related to high food prices and poverty.[1][5] A lack of breastfeeding may contribute, as may a number of infectious diseases such as: gastroenteritis, pneumonia, malaria, and measles, which increase nutrient requirements.[5] There are two main types of undernutrition: protein-energy malnutrition and dietary deficiencies.[12] Protein-energy malnutrition has two severe forms: marasmus (a lack of protein and calories) and kwashiorkor (a lack of just protein).[2] Common micronutrient deficiencies include: a lack of iron, iodine, and vitamin A.[2] During pregnancy, due to the body's increased need, deficiencies may become more common.[13] In some developing countries, overnutrition in the form of obesity is beginning to present within the same communities as undernutrition.[14] Other causes of malnutrition include anorexia nervosa and bariatric surgery.[15][16]

Efforts to improve nutrition are some of the most effective forms of development aid. Breastfeeding can reduce rates of malnutrition and death in children,[1] and efforts to promote the practice increase the rates of breastfeeding.[8] In young children, providing food (in addition to breastmilk) between six months and two years of age improves outcomes.[8] There is also good evidence supporting the supplementation of a number of micronutrients to women during pregnancy and among young children in the developing world.[8] To get food to people who need it most, both delivering food and providing money so people can buy food within local markets are effective.[6][17] Simply feeding students at school is insufficient.[6] Management of severe malnutrition within the person's home with ready-to-use therapeutic foods is possible much of the time.[8] In those who have severe malnutrition complicated by other health problems, treatment in a hospital setting is recommended.[8] This often involves managing low blood sugar and body temperature, addressing dehydration, and gradual feeding.[8][18] Routine antibiotics are usually recommended due to the high risk of infection.[18] Longer-term measures include: improving agricultural practices,[7] reducing poverty, improving sanitation, and the empowerment of women.[6]

There were 815 million undernourished people in the world in 2017 (11% of the total population).[10] This is a reduction of 176 million people since 1990 when 23% were undernourished.[10][19] In 2012 it was estimated that another billion people had a lack of vitamins and minerals.[6] In 2015, protein-energy malnutrition was estimated to have resulted in 323,000 deaths—down from 510,000 deaths in 1990.[11][20] Other nutritional deficiencies, which include iodine deficiency and iron deficiency anemia, result in another 83,000 deaths.[11] In 2010, malnutrition was the cause of 1.4% of all disability adjusted life years.[6][21] About a third of deaths in children are believed to be due to undernutrition, although the deaths are rarely labelled as such.[5] In 2010, it was estimated to have contributed to about 1.5 million deaths in women and children,[22] though some estimate the number may be greater than 3 million.[8] An additional 165 million children were estimated to have stunted growth from malnutrition in 2013.[8] Undernutrition is more common in developing countries.[23] Certain groups have higher rates of undernutrition, including women—in particular while pregnant or breastfeeding—children under five years of age, and the elderly. In the elderly, undernutrition becomes more common due to physical, psychological, and social factors.[24]

Definitions

Child in the United States with signs of Kwashiorkor, a dietary protein deficiency.

Unless specifically mentioned otherwise, the term malnutrition refers to undernutrition for the remainder of this article. Malnutrition can be divided into two different types, SAM and MAM. SAM refers to children with severe acute malnutrition. MAM refers to moderate acute malnutrition.[25]

Undernutrition and overnutrition

Malnutrition is caused by eating a diet in which nutrients are not enough or are too much such that it causes health problems.[26] It is a category of diseases that includes undernutrition and overnutrition.[27] Overnutrition can result in obesity and being overweight. In some developing countries, overnutrition in the form of obesity is beginning to present within the same communities as undernutrition.[28]

However, the term malnutrition is commonly used to refer to undernutrition only.[29] This applies particularly to the context of development cooperation. Therefore, "malnutrition" in documents by the World Health Organization, UNICEF, Save the Children or other international non-governmental organizations (NGOs) usually is equated to undernutrition.

Protein-energy malnutrition

Undernutrition is sometimes used as a synonym of protein–energy malnutrition (PEM).[2] While other include both micronutrient deficiencies and protein energy malnutrition in its definition.[12] It differs from calorie restriction in that calorie restriction may not result in negative health effects. The term hypoalimentation means underfeeding.[30]

The term "severe malnutrition" or "severe undernutrition" is often used to refer specifically to PEM.[31] PEM is often associated with micronutrient deficiency.[31] Two forms of PEM are kwashiorkor and marasmus, and they commonly coexist.[26]

Kwashiorkor

Kwashiorkor is mainly caused by inadequate protein intake.[26] The main symptoms are edema, wasting, liver enlargement, hypoalbuminaemia, steatosis, and possibly depigmentation of skin and hair.[26] Kwashiorkor is further identified by swelling of the belly, which is deceiving of actual nutritional status.[32] The term means ‘displaced child’ and is derived from a Ghana language of West Africa, means "the sickness the older one gets when the next baby is born," as this is when the older child is deprived of breast feeding and weaned to a diet composed largely of carbohydrates.[33]

Marasmus

Marasmus (‘to waste away’) is caused by an inadequate intake of protein and energy. The main symptoms are severe wasting, leaving little or no edema, minimal subcutaneous fat, severe muscle wasting, and non-normal serum albumin levels.[26] Marasmus can result from a sustained diet of inadequate energy and protein, and the metabolism adapts to prolong survival.[26] It is traditionally seen in famine, significant food restriction, or more severe cases of anorexia.[26] Conditions are characterized by extreme wasting of the muscles and a gaunt expression.[32]

Undernutrition, hunger

Undernutrition encompasses stunted growth (stunting), wasting, and deficiencies of essential vitamins and minerals (collectively referred to as micronutrients). The term hunger, which describes a feeling of discomfort from not eating, has been used to describe undernutrition, especially in reference to food insecurity.[34]

Definition by Gomez

In 1956, Gómez and Galvan studied factors associated with death in a group of malnourished (undernourished) children in a hospital in Mexico City, Mexico and defined categories of malnutrition: first, second, and third degree.[35] The degrees were based on weight below a specified percentage of median weight for age.[36] The risk of death increases with increasing degree of malnutrition.[35] An adaptation of Gomez's original classification is still used today. While it provides a way to compare malnutrition within and between populations, the classification has been criticized for being "arbitrary" and for not considering overweight as a form of malnutrition. Also, height alone may not be the best indicator of malnutrition; children who are born prematurely may be considered short for their age even if they have good nutrition.[37]
 
Degree of PEM % of desired body weight for age and sex
Normal 90%-100%
Mild: Grade I (1st degree) 75%-89%
Moderate: Grade II (2nd degree) 60%-74%
Severe: Grade III (3rd degree) <60 td="">
SOURCE:"Serum Total Protein and Albumin Levels in Different Grades of Protein Energy Malnutrition"[32]

Definition by Waterlow

John Conrad Waterlow established a new classification for malnutrition.[38] Instead of using just weight for age measurements, the classification established by Waterlow combines weight-for-height (indicating acute episodes of malnutrition) with height-for-age to show the stunting that results from chronic malnutrition.[39] One advantage of the Waterlow classification over the Gomez classification is that weight for height can be examined even if ages are not known.[38]
 
Degree of PEM Stunting (%) Height for age Wasting (%) Weight for height
Normal: Grade 0 >95% >90%
Mild: Grade I 87.5-95% 80-90%
Moderate: Grade II 80-87.5% 70-80%
Severe: Grade III <80 td=""> <70 td="">
SOURCE: "Classification and definition of protein-calorie malnutrition." by Waterlow, 1972[38]

These classifications of malnutrition are commonly used with some modifications by WHO.[36]

Effects

Child of a sharecropper with malnutrition and rickets, 1935

Malnutrition increases the risk of infection and infectious disease, and moderate malnutrition weakens every part of the immune system.[40] For example, it is a major risk factor in the onset of active tuberculosis.[41] Protein and energy malnutrition and deficiencies of specific micronutrients (including iron, zinc, and vitamins) increase susceptibility to infection.[40] Malnutrition affects HIV transmission by increasing the risk of transmission from mother to child and also increasing replication of the virus.[40] In communities or areas that lack access to safe drinking water, these additional health risks present a critical problem. Lower energy and impaired function of the brain also represent the downward spiral of malnutrition as victims are less able to perform the tasks they need to in order to acquire food, earn an income, or gain an education.

Hypoglycemia (low blood sugar) can result from a child not eating for 4 to 6 hours. Hypoglycemia should be considered if there is lethargy, limpness, convulsion, or loss of consciousness. If blood sugar can be measured immediately and quickly, perform a finger or heel stick.

Signs

In those with malnutrition some of the signs of dehydration differ.[42] Children; however, may still be interested in drinking, have decreased interactions with the world around them, have decreased urine output, and may be cool to touch.[42]
 
Site Sign
Face Moon face (kwashiorkor), simian facies (marasmus)
Eye Dry eyes, pale conjunctiva, Bitot's spots (vitamin A), periorbital edema
Mouth Angular stomatitis, cheilitis, glossitis, spongy bleeding gums (vitamin C), parotid enlargement
Teeth Enamel mottling, delayed eruption
Hair Dull, sparse, brittle hair, hypopigmentation, flag sign (alternating bands of light and normal color), broomstick eyelashes, alopecia
Skin Loose and wrinkled (marasmus), shiny and edematous (kwashiorkor), dry, follicular hyperkeratosis, patchy hyper- and hypopigmentation, erosions, poor wound healing
Nail Koilonychia, thin and soft nail plates, fissures or ridges
Musculature Muscles wasting, particularly in the buttocks and thighs
Skeletal Deformities usually a result of calcium, vitamin D, or vitamin C deficiencies
Abdomen Distended - hepatomegaly with fatty liver, ascites may be present
Cardiovascular Bradycardia, hypotension, reduced cardiac output, small vessel vasculopathy
Neurologic Global development delay, loss of knee and ankle reflexes, poor memory
Hematological Pallor, petechiae, bleeding diathesis
Behavior Lethargic, apathetic
Source: "Protein Energy Malnutrition"[36]

Cognitive development

Protein-calorie malnutrition can cause cognitive impairments. For humans, "critical period varies from the final third of gestation to the first 2 years of life".[43] Iron deficiency anemia in children under two years of age likely affects brain function acutely and probably also chronically. Folate deficiency has been linked to neural tube defects.[44]

Malnutrition in the form of iodine deficiency is "the most common preventable cause of mental impairment worldwide." "Even moderate deficiency, especially in pregnant women and infants, lowers intelligence by 10 to 15 I.Q. points, shaving incalculable potential off a nation's development. The most visible and severe effects — disabling goiters, cretinism and dwarfism — affect a tiny minority, usually in mountain villages. But 16 percent of the world's people have at least mild goiter, a swollen thyroid gland in the neck."[45]

Causes

Union Army soldier on his release from Andersonville prison, 1865

Major causes of malnutrition include poverty and food prices, dietary practices and agricultural productivity, with many individual cases being a mixture of several factors. Clinical malnutrition, such as cachexia, is a major burden also in developed countries. Various scales of analysis also have to be considered in order to determine the sociopolitical causes of malnutrition. For example, the population of a community that is within poor governments, may be at risk if the area lacks health-related services, but on a smaller scale certain households or individuals may be at an even higher risk due to differences in income levels, access to land, or levels of education.[46]

Diseases

Malnutrition can be a consequence of health issues such as gastroenteritis[47] or chronic illness,[48] especially the HIV/AIDS pandemic.[49] Diarrhea and other infections can cause malnutrition through decreased nutrient absorption, decreased intake of food, increased metabolic requirements, and direct nutrient loss.[50] Parasite infections, in particular intestinal worm infections (helminthiasis), can also lead to malnutrition.[50] A leading cause of diarrhea and intestinal worm infections in children in developing countries is lack of sanitation and hygiene.

People may become malnourished due to abnormal nutrient loss (due to diarrhea or chronic illness affecting the small bowel).[36][51] This conditions may include Crohn's disease or untreated coeliac disease.[4][9][52] Malnutrition may also occur due to increased energy expenditure (secondary malnutrition).[36][51]

Dietary practices

Undernutrition

A lack of adequate breastfeeding leads to malnutrition in infants and children, associated with the deaths of an estimated one million children annually. Illegal advertising of breast milk substitutes continues three decades after its 1981 prohibition under the WHO International Code of Marketing Breast Milk Substitutes.[53]

Maternal malnutrition can also factor into the poor health or death of a baby. Over 800,000 neonatal death have occurred because of deficient growth of the fetus in the mother's womb.[54]

Deriving too much of one's diet from a single source, such as eating almost exclusively corn or rice, can cause malnutrition. This may either be from a lack of education about proper nutrition, or from only having access to a single food source.[55]

It is not just the total amount of calories that matters but specific nutritional deficiencies such as vitamin A deficiency, iron deficiency or zinc deficiency can also increase risk of death.[56]

Overnutrition

Overnutrition caused by overeating is also a form of malnutrition. In the United States, more than half of all adults are now overweight — a condition that, like hunger, increases susceptibility to disease and disability, reduces worker productivity, and lowers life expectancy.[57] Overeating is much more common in the United States, where for the majority of people, access to food is not an issue. Many parts of the world have access to a surplus of non-nutritious food, in addition to increased sedentary lifestyles. Yale psychologist Kelly Brownell calls this a "toxic food environment" where fat and sugar laden foods have taken precedence over healthy nutritious foods.[57]

The issue in these developed countries is choosing the right kind of food. More fast food is consumed per capita in the United States than in any other country. The reason for this mass consumption of fast food is its affordability and accessibility. Often fast food, low in cost and nutrition, is high in calories and heavily promoted. When these eating habits are combined with increasingly urbanized, automated, and more sedentary lifestyles, it becomes clear why weight gain is difficult to avoid.[58]

Not only does obesity occur in developed countries, problems are also occurring in developing countries in areas where income is on the rise.[57] Overeating is also a problem in countries where hunger and poverty persist. In China, consumption of high-fat foods has increased while consumption of rice and other goods has decreased.[57]

Overeating leads to many diseases, such as heart disease and diabetes, that may result in death.

Poverty and food prices

A child with extreme malnutrition

In Bangladesh, poor socioeconomic position was associated with chronic malnutrition since it inhibits purchase of nutritious foods such as milk, meat, poultry, and fruits.[59] As much as food shortages may be a contributing factor to malnutrition in countries with lack of technology, the FAO (Food and Agriculture Organization) has estimated that eighty percent of malnourished children living in the developing world live in countries that produce food surpluses.[57] The economist Amartya Sen observed that, in recent decades, famine has always been a problem of food distribution and/or poverty, as there has been sufficient food to feed the whole population of the world. He states that malnutrition and famine were more related to problems of food distribution and purchasing power.[60]

It is argued that commodity speculators are increasing the cost of food. As the real estate bubble in the United States was collapsing, it is said that trillions of dollars moved to invest in food and primary commodities, causing the 2007–2008 food price crisis.[61]

The use of biofuels as a replacement for traditional fuels raises the price of food.[62] The United Nations special rapporteur on the right to food, Jean Ziegler proposes that agricultural waste, such as corn cobs and banana leaves, rather than crops themselves be used as fuel.[63]

Agricultural productivity

Local food shortages can be caused by a lack of arable land, adverse weather, lower farming skills such as crop rotation, or by a lack of technology or resources needed for the higher yields found in modern agriculture, such as fertilizers, pesticides, irrigation, machinery and storage facilities. As a result of widespread poverty, farmers cannot afford or governments cannot provide the resources necessary to improve local yields. The World Bank and some wealthy donor countries also press nations that depend on aid to cut or eliminate subsidized agricultural inputs such as fertilizer, in the name of free market policies even as the United States and Europe extensively subsidized their own farmers.[64][65] Many, if not most, farmers cannot afford fertilizer at market prices, leading to low agricultural production and wages and high, unaffordable food prices.[64] Reasons for the unavailability of fertilizer include moves to stop supplying fertilizer on environmental grounds, cited as the obstacle to feeding Africa by the Green Revolution pioneers Norman Borlaug and Keith Rosenberg.[66]

Future threats

There are a number of potential disruptions to global food supply that could cause widespread malnutrition.

Global warming is of importance to food security, with 95 percent of all malnourished peoples living in the relatively stable climate region of the sub-tropics and tropics. According to the latest IPCC reports, temperature increases in these regions are "very likely."[67] Even small changes in temperatures can lead to increased frequency of extreme weather conditions.[67] Many of these have great impact on agricultural production and hence nutrition. For example, the 1998–2001 central Asian drought brought about an 80 percent livestock loss and 50 percent reduction in wheat and barley crops in Iran.[68] Similar figures were present in other nations. An increase in extreme weather such as drought in regions such as Sub-Saharan Africa would have even greater consequences in terms of malnutrition. Even without an increase of extreme weather events, a simple increase in temperature reduces the productivity of many crop species, also decreasing food security in these regions.[67][69]

Colony collapse disorder is a phenomenon where bees die in large numbers.[70] Since many agricultural crops worldwide are pollinated by bees, this represents a threat to the supply of food.[71]
An epidemic of wheat stem rust caused by race Ug99 is currently spreading across Africa and into Asia and, it is feared, could wipe out more than 80 percent of the world’s wheat crops.[72][73]

Prevention

Irrigation canals have opened dry desert areas of Egypt to agriculture.

Food security

The effort to bring modern agricultural techniques found in the West, such as nitrogen fertilizers and pesticides, to Asia, called the Green Revolution, resulted in decreases in malnutrition similar to those seen earlier in Western nations. This was possible because of existing infrastructure and institutions that are in short supply in Africa, such as a system of roads or public seed companies that made seeds available.[74] Investments in agriculture, such as subsidized fertilizers and seeds, increases food harvest and reduces food prices.[64][75] For example, in the case of Malawi, almost five million of its 13 million people used to need emergency food aid. However, after the government changed policy and subsidies for fertilizer and seed were introduced against World Bank strictures, farmers produced record-breaking corn harvests as production leaped to 3.4 million in 2007 from 1.2 million in 2005, making Malawi a major food exporter.[64] This lowered food prices and increased wages for farm workers.[64] Such investments in agriculture are still needed in other African countries like the Democratic Republic of the Congo. The country has one of the highest prevalence of malnutrition even though it is blessed with great agricultural potential John Ulimwengu explains in his article for D+C.[76] Proponents for investing in agriculture include Jeffrey Sachs, who has championed the idea that wealthy countries should invest in fertilizer and seed for Africa’s farmers.[64][77]
New technology in agricultural production also has great potential to combat undernutrition.[78] By improving agricultural yields, farmers could reduce poverty by increasing income as well as open up area for diversification of crops for household use. The World Bank itself claims to be part of the solution to malnutrition, asserting that the best way for countries to succeed in breaking the cycle of poverty and malnutrition is to build export-led economies that will give them the financial means to buy foodstuffs on the world market.

Economics

There is a growing realization among aid groups that giving cash or cash vouchers instead of food is a cheaper, faster, and more efficient way to deliver help to the hungry, particularly in areas where food is available but unaffordable.[79] The UN's World Food Program, the biggest non-governmental distributor of food, announced that it will begin distributing cash and vouchers instead of food in some areas, which Josette Sheeran, the WFP's executive director, described as a "revolution" in food aid.[79][80] The aid agency Concern Worldwide is piloting a method through a mobile phone operator, Safaricom, which runs a money transfer program that allows cash to be sent from one part of the country to another.[79]

However, for people in a drought living a long way from and with limited access to markets, delivering food may be the most appropriate way to help.[79] Fred Cuny stated that "the chances of saving lives at the outset of a relief operation are greatly reduced when food is imported. By the time it arrives in the country and gets to people, many will have died."[81] U.S. law, which requires buying food at home rather than where the hungry live, is inefficient because approximately half of what is spent goes for transport.[82] Cuny further pointed out "studies of every recent famine have shown that food was available in-country — though not always in the immediate food deficit area" and "even though by local standards the prices are too high for the poor to purchase it, it would usually be cheaper for a donor to buy the hoarded food at the inflated price than to import it from abroad."[83]

Ethiopia has been pioneering a program that has now become part of the World Bank's prescribed method for coping with a food crisis and had been seen by aid organizations as a model of how to best help hungry nations. Through the country's main food assistance program, the Productive Safety Net Program, Ethiopia has been giving rural residents who are chronically short of food, a chance to work for food or cash. Foreign aid organizations like the World Food Program were then able to buy food locally from surplus areas to distribute in areas with a shortage of food.[84] Ethiopia been pioneering a program, and Brazil has established a recycling program for organic waste that benefits farmers, urban poor, and the city in general. City residents separate organic waste from their garbage, bag it, and then exchange it for fresh fruit and vegetables from local farmers. As a result, the country's waste is reduced and the urban poor get a steady supply of nutritious food.[58]

World population

Restricting population size is a proposed solution. Thomas Malthus argued that population growth could be controlled by natural disasters and voluntary limits through "moral restraint."[85] Robert Chapman suggests that an intervention through government policies is a necessary ingredient of curtailing global population growth.[86] However, there are many who believe that the world has more than enough resources to sustain its population. Instead, these theorists point to unequal distribution of resources and under- or unutilized arable land as the cause for malnutrition problems. For example, Amartya Sen advocates that, "no matter how a famine is caused, methods of breaking it call for a large supply of food in the public distribution system. This applies not only to organizing rationing and control, but also to undertaking work programmes and other methods of increasing purchasing power for those hit by shifts in exchange entitlements in a general inflationary situation."[60]

Food sovereignty

One suggested policy framework to resolve access issues is termed food sovereignty—the right of peoples to define their own food, agriculture, livestock, and fisheries systems, in contrast to having food largely subjected to international market forces. Food First is one of the primary think tanks working to build support for food sovereignty. Neoliberals advocate for an increasing role of the free market.

Health facilities

Another possible long term solution would be to increase access to health facilities to rural parts of the world. These facilities could monitor undernourished children, act as supplemental food distribution centers, and provide education on dietary needs. These types of facilities have already proven very successful in countries such as Peru and Ghana.[89][90]

Breastfeeding

As of 2016 is estimated that about 821,000 deaths of children less than five years old could be prevented globally per year through more widespread breastfeeding.[91] In addition to reducing infant death, breast milk feeding provides an important source of micronutrients, clinically proven to bolster the immune system of children, and provide long-term defenses against non-communicable and allergic diseases.[92] Breastfeeding has also been shown to improve cognitive abilities in children, with a strong correlation to individual educational achievements.[92][93] As previously noted, lack of proper breastfeeding is a major factor in child mortality rates, and a primary determinant of disease development for children. The medical community recommends exclusively breastfeeding infants for 6 months, with nutritional whole food supplementation and continued breastfeeding up to 2 years or older for overall optimal health outcomes.[93][94][95] Exclusive breastfeeding is defined as only giving an infant breast milk for six months as a source of food and nutrition.[93][95] This means no other liquids, including water or semi-solid foods.[95]

Barriers to breastfeeding

Breastfeeding is noted as one of the most cost effective medical interventions for providing beneficial child health.[94] While there are considerable differences within developed and developing countries: income, employment, social norms, and access to healthcare were found to be universal determinants of whether a mother breast of formula fed their children.[93][94] Community based healthcare workers have helped alleviate financial barriers faced by newly made mothers, and provided a viable alternative to traditional and expensive hospital based medical care.[93] Recent studies based upon surveys conducted from 1995-2010 shows exclusive breastfeeding rates have gone up globally, from 33% to 39%.[95] Despite the growth rates, medical professionals acknowledge the need for improvement given the importance of exclusive breastfeeding.[95]

Global initiatives

Food security and global malnutrition has long been a topic of international concern, with one of the first official global documents addressing it being the 1948 Universal Declaration of Human Rights(UDHR). Within this document it stated that access to food was part of an adequate right to a standard of living.[96] The Right to food was asserted in the International Covenant on Economic, Social and Cultural Rights, a treaty adopted by the United Nations General Assembly on December 16, 1966. The Right to food is a human right for people to feed themselves in dignity, be free from hunger, food insecurity, and malnutrition.[97] As of 2018, the treaty has been signed by 166 countries, by signing states agreed to take steps to the maximum of their available resources to achieve the right to adequate food.

However, after the 1966 International Covenant the global concern for the access to sufficient food only became more present, leading to the first ever World Food Conference that was held in 1974 in Rome, Italy. The Universal Declaration on the Eradication of Hunger and Malnutrition was a UN resolution adopted November 16, 1974 by all 135 countries that attended the 1974 World Food Conference.[98] This non-legally binding document set forth certain aspirations for countries to follow to sufficiently take action on the global food problem. Ultimately this document outline and provided guidance as to how the international community as one could work towards fighting and solving the growing global issue of malnutrition and hunger.

Adoption of the right to food was included in the Additional Protocol to the American Convention on Human Rights in the area of Economic, Social, and Cultural Rights, this 1978 document was adopted by many countries in the Americas, the purpose of the document is, "to consolidate in this hemisphere, within the framework of democratic institutions, a system of personal liberty and social justice based on respect for the essential rights of man."[99]

The next document in the timeline of global inititaves for malnutrition was the 1996 Rome Declaration on World Food Security, organized by the Food and Agriculture Organization. This document reaffirmed the right to have access to safe and nutritous food by everyone, also considering that everyone gets sufficient food, and set the goals for all nations to improve their commitment to food security by halfing their amount of undernourished people by 2015.[100] In 2004 the Food and Agriculture Organization adopted the Right to Food Guidelines, which offered states a framework of how to increase the right to food on a national basis.

One of the most recent and powerful global policies to reduce hunger and poverty are the Sustainable Development Goals. In particular Goal 2: Zero hunger sets globally agreed targets to end hunger, achieve food security and improved nutrition and promote sustainable agriculture.[101] The partnership Compact2025, led by IFPRI with the involvement of UN organisations, NGOs and private foundations develops and disseminates evidence-based advice to politicians and other decision-makers aimed at ending hunger and undernutrition in the coming 10 years, by 2025.[102][103]

In April 2012, the Food Assistance Convention was signed, the world's first legally binding international agreement on food aid. The May 2012 Copenhagen Consensus recommended that efforts to combat hunger and malnutrition should be the first priority for politicians and private sector philanthropists looking to maximize the effectiveness of aid spending. They put this ahead of other priorities, like the fight against malaria and AIDS.[104]

The EndingHunger campaign is an online communication campaign aimed at raising awareness of the hunger problem. It has many worked through viral videos depicting celebrities voicing their anger about the large number of hungry people in the world. Another initiative focused on improving the hunger situation by improving nutrition is the Scaling up Nutrition movement (SUN). Started in 2010 this movement of people from governments, civil society, the United Nations, donors, businesses and researchers, publishes a yearly progress report on the changes in their 55 partner countries.[105]

Treatment

A malnourished Afghan child being treated by a medical team.
 
A Somali boy receiving treatment for malnourishment at a health facility.
 
In response to child malnutrition, the Bangladeshi government recommends ten steps for treating severe malnutrition. They are to prevent or treat dehydration, low blood sugar, low body temperature, infection, correct electrolyte imbalances and micronutrient deficiencies, start feeding cautiously, achieve catch-up growth, provide psychological support, and prepare for discharge and follow-up after recovery.[106]

Among those who are hospitalized, nutritional support improves protein, calorie intake and weight.[107]

Food

The evidence for benefit of supplementary feeding is poor.[108] This is due to the small amount of research done on this treatment.

Specially formulated foods do however appear useful in those from the developing world with moderate acute malnutrition.[109] In young children with severe acute malnutrition it is unclear if ready-to-use therapeutic food differs from a normal diet.[110] They may have some benefits in humanitarian emergencies as they can be eaten directly from the packet, do not require refrigeration or mixing with clean water, and can be stored for years.[111]

In those who are severely malnourished, feeding too much too quickly can result in refeeding syndrome.[112] This can result regardless of route of feeding and can present itself a couple of days after eating with heart failure, dysrhythmias and confusion that can result in death.[112][113]

Manufacturers are trying to fortify everyday foods with micronutrients that can be sold to consumers such as wheat flour for Beladi bread in Egypt or fish sauce in Vietnam and the iodization of salt.[111]

For example, flour has been fortified with iron, zinc, folic acid and other B vitamins such as thiamine, riboflavin, niacin and vitamin B12.[56]

Micronutrients

Treating malnutrition, mostly through fortifying foods with micronutrients (vitamins and minerals), improves lives at a lower cost and shorter time than other forms of aid, according to the World Bank.[114] The Copenhagen Consensus, which look at a variety of development proposals, ranked micronutrient supplements as number one.[115][82]

In those with diarrhea, once an initial four-hour rehydration period is completed, zinc supplementation is recommended. Daily zinc increases the chances of reducing the severity and duration of the diarrhea, and continuing with daily zinc for ten to fourteen days makes diarrhea less likely recur in the next two to three months.[116]

In addition, malnourished children need both potassium and magnesium.[106] This can be obtained by following the above recommendations for the dehydrated child to continue eating within two to three hours of starting rehydration,[106][116] and including foods rich in potassium as above. Low blood potassium is worsened when base (as in Ringer's/Hartmann's) is given to treat acidosis without simultaneously providing potassium.[116] As above, available home products such as salted and unsalted cereal water, salted and unsalted vegetable broth can be given early during the course of a child's diarrhea along with continued eating.[116] Vitamin A, potassium, magnesium, and zinc should be added with other vitamins and minerals if available.[106]

For a malnourished child with diarrhea from any cause, this should include foods rich in potassium such as bananas, green coconut water, and unsweetened fresh fruit juice.[116]

Diarrhea

Examples of commercially available oral rehydration salts (Nepal on left, Peru on right).

The World Health Organization (WHO) recommends rehydrating a severely undernourished child who has diarrhea relatively slowly. The preferred method is with fluids by mouth using a drink called oral rehydration solution (ORS). The oral rehydration solution is both slightly sweet and slightly salty and the one recommended in those with severe undernutrition should have half the usual sodium and greater potassium. Fluids by nasogastric tube may be use in those who do not drink. Intravenous fluids are recommended only in those who have significant dehydration due to their potential complications. These complications include congestive heart failure.[42] Over time, ORS developed into ORT, or oral rehydration therapy, which focused on increasing fluids by supplying salts, carbohydrates, and water. This switch from type of fluid to amount of fluid was crucial in order to prevent dehydration from diarrhea.[117]

Breast feeding and eating should resume as soon as possible.[42] Drinks such as soft drinks, fruit juices, or sweetened teas are not recommended as they contain too much sugar and may worsen diarrhea.[118] Broad spectrum antibiotics are recommended in all severely undernourished children with diarrhea requiring admission to hospital.[42]

To prevent dehydration readily available fluids, preferably with a modest amount of sugars and salt such as vegetable broth or salted rice water, may be used. The drinking of additional clean water is also recommended. Once dehydration develops oral rehydration solutions are preferred. As much of these drinks as the person wants can be given, unless there are signs of swelling. If vomiting occurs, fluids can be paused for 5–10 minutes and then restarting more slowly. Vomiting rarely prevents rehydration as fluid are still absorbed and the vomiting rarely last long.[118] A severely malnourished child with what appears to be dehydration but who has not had diarrhea should be treated as if they have an infection.[42]

For babies a dropper or syringe without the needle can be used to put small amounts of fluid into the mouth; for children under 2, a teaspoon every one to two minutes; and for older children and adults, frequent sips directly from a cup.[116] After the first two hours, rehydration should be continued at the same or slower rate, determined by how much fluid the child wants and any ongoing diarrheal loses. After the first two hours of rehydration it is recommended that to alternate between rehydration and food.[106]

In 2003, WHO and UNICEF recommended a reduced-osmolarity ORS which still treats dehydration but also reduced stool volume and vomiting. Reduced-osmolarity ORS is the current standard ORS with reasonably wide availability.[119][120] For general use, one packet of ORS (glucose sugar, salt, potassium chloride, and trisodium citrate) is added to one liter of water; however, for malnourished children it is recommended that one packet of ORS be added to two liters of water along with an extra 50 grams of sucrose sugar and some stock potassium solution.[121]

Malnourished children have an excess of body sodium.[106] Recommendations for home remedies agree with one liter of water (34 oz.) and 6 teaspoons sugar and disagree regarding whether it is then one teaspoon of salt added or only 1/2, with perhaps most sources recommending 1/2 teaspoon of added salt to one liter water.[116][122][123][124]

Low blood sugar

Hypoglycemia, whether known or suspected, can be treated with a mixture of sugar and water. If the child is conscious, the initial dose of sugar and water can be given by mouth.[125] If the child is unconscious, give glucose by intravenous or nasogastric tube. If seizures occur after despite glucose, rectal diazepam is recommended. Blood sugar levels should be re-checked on two hour intervals.[106]

Hypothermia

Hypothermia can occur. To prevent or treat this, the child can be kept warm with covering including of the head or by direct skin-to-skin contact with the mother or father and then covering both parent and child. Prolonged bathing or prolonged medical exams should be avoided. Warming methods are usually most important at night.[106]

Epidemiology

Percentage of population affected by undernutrition by country in 2012
 
Disability-adjusted life year for nutritional deficiencies per 100,000 inhabitants in 2004. Nutritional deficiencies included: protein-energy malnutrition, iodine deficiency, vitamin A deficiency, and iron deficiency anaemia.[126]
 

The figures provided in this section on epidemiology all refer to undernutrition even if the term malnutrition is used which, by definition, could also apply to too much nutrition.

People affected

There were 815 million undernourished people in the world in 2017.[10] This was 176 million fewer people than in 1990 when it was 991 million undernourished people.[10] This is despite the world's farmers producing enough food to feed around 12 billion people – almost double the current world population.[127]

Malnutrition, as of 2010, was the cause of 1.4% of all disability adjusted life years.[21]
 
Number of undernourished globally
Year 1970 1980 1990 1995 2005 2007/08 2014/16
Number in millions[128][129]

843 788 848 923 793
Percentage in the developing world[128][130][131] 37% 28% 20%
16% 17% 13.5%

Mortality

Deaths from nutritional deficiencies per million persons in 2012 
 
  0-4
  5-8
  9-13
  14-23
  24-34
  35-56
  57-91
  92-220
  221-365
  366-1,207

Mortality due to malnutrition accounted for 58 percent of the total mortality in 2006: "In the world, approximately 62 million people, all causes of death combined, die each year. One in twelve people worldwide is malnourished and according to the Save the Children 2012 report, one in four of the world’s children are chronically malnourished.[132] In 2006, more than 36 million died of hunger or diseases due to deficiencies in micronutrients".[133]

In 2010 protein-energy malnutrition resulted in 600,000 deaths down from 883,000 deaths in 1990.[134] Other nutritional deficiencies, which include iodine deficiency and iron deficiency anemia, result in another 84,000 deaths.[134] In 2010 malnutrition caused about 1.5 million deaths in women and children.[22]

According to the World Health Organization, malnutrition is the biggest contributor to child mortality, present in half of all cases.[135] Six million children die of hunger every year.[136] Underweight births and intrauterine growth restrictions cause 2.2 million child deaths a year. Poor or non-existent breastfeeding causes another 1.4 million. Other deficiencies, such as lack of vitamin A or zinc, for example, account for 1 million. Malnutrition in the first two years is irreversible. Malnourished children grow up with worse health and lower education achievement. Their own children tend to be smaller. Malnutrition was previously[when?] seen as something that exacerbates the problems of diseases such as measles, pneumonia and diarrhea, but malnutrition actually causes diseases, and can be fatal in its own right.[135]

Society and culture

Roughly $300 million of aid goes to basic nutrition each year, less than $2 for each child below two in the 20 worst affected countries.[135] In contrast, HIV/AIDS, which causes fewer deaths than child malnutrition, received $2.2 billion—$67 per person with HIV in all countries.[135]

The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), a member of the CGIAR consortium, partners with farmers, governments, researchers and NGOs to help farmers grow nutritious crops, such as chickpea, groundnut, pigeonpea, millet and sorghum. This helps their communities have more balanced diets and become more resilient to pests and drought. The Harnessing Opportunities for Productivity Enhancement of Sorghum and Millets in Sub-Saharan Africa and the Indian-Subcontinent (HOPE) project, for example, is increasing yields of finger millet in Tanzania by encouraging farmers to grow improved varieties. Finger millet is very high in calcium, rich in iron and fiber, and has a better energy content than other cereals. These characteristics make it ideal for feeding to infants and the elderly.[137]

Some organizations have begun working with teachers, policymakers, and managed food service contractors to mandate improved nutritional content and increased nutritional resources in school cafeterias from primary to university-level institutions. Health and nutrition have been proven to have close links with overall educational success.[138]

The verb form is "malnourish"; "malnourishment" is sometimes used instead of "malnutrition."

Special populations

Undernutrition is an important determinant of maternal and child health, accounting for more than a third of child deaths and more than 10 percent of the total global disease burden according to 2008 studies.[34]

Children

Malnourished children in Niger, during the 2005 famine.

The World Health Organization estimates that malnutrition accounts for 54 percent of child mortality worldwide,[31] about 1 million children.[139] Another estimate also by WHO states that childhood underweight is the cause for about 35% of all deaths of children under the age of five years worldwide.[140]

As underweight children are more vulnerable to almost all infectious diseases, the indirect disease burden of malnutrition is estimated to be an order of magnitude higher than the disease burden of the direct effects of malnutrition.[140] The combination of direct and indirect deaths from malnutrition caused by unsafe water, sanitation and hygiene (WASH) practices is estimated to lead to 860,000 deaths per year in children under five years of age.[140]

Women

Gender

Researchers from the Centre for World Food Studies in 2003 found that the gap between levels of undernutrition in men and women is generally small, but that the gap varies from region to region and from country to country.[141] These small-scale studies showed that female undernutrition prevalence rates exceeded male undernutrition prevalence rates in South/Southeast Asia and Latin America and were lower in Sub-Saharan Africa.[141] Datasets for Ethiopia and Zimbabwe reported undernutrition rates between 1.5 and 2 times higher in men than in women; however, in India and Pakistan, datasets rates of undernutrition were 1.5-2 times higher in women than in men. Intra-country variation also occurs, with frequent high gaps between regional undernutrition rates.[141] Gender inequality in nutrition in some countries such as India is present in all stages of life.[142]

Studies on nutrition concerning gender bias within households look at patterns of food allocation, and one study from 2003 suggested that women often receive a lower share of food requirements than men.[141] Gender discrimination, gender roles, and social norms affecting women can lead to early marriage and childbearing, close birth spacing, and undernutrition, all of which contribute to malnourished mothers.[59]

Within the household, there may be differences in levels of malnutrition between men and women, and these differences have been shown to vary significantly from one region to another, with problem areas showing relative deprivation of women.[141] Samples of 1000 women in India in 2008 demonstrated that malnutrition in women is associated with poverty, lack of development and awareness, and illiteracy.[142] The same study showed that gender discrimination in households can prevent a woman's access to sufficient food and healthcare.[142] How socialization affects the health of women in Bangladesh, Najma Rivzi explains in an article about a research program on this topic.[143] In some cases, such as in parts of Kenya in 2006, rates of malnutrition in pregnant women were even higher than rates in children.[144]

Women in some societies are traditionally given less food than men since men are perceived to have heavier workloads.[145] Household chores and agricultural tasks can in fact be very arduous and require additional energy and nutrients; however, physical activity, which largely determines energy requirements, is difficult to estimate.[141]

Physiology

Women have unique nutritional requirements, and in some cases need more nutrients than men; for example, women need twice as much calcium as men.[145]

Pregnancy and breastfeeding

During pregnancy and breastfeeding, women must ingest enough nutrients for themselves and their child, so they need significantly more protein and calories during these periods, as well as more vitamins and minerals (especially iron, iodine, calcium, folic acid, and vitamins A, C, and K).[145] In 2001 the FAO of the UN reported that iron deficiency afflicted 43 percent of women in developing countries and increased the risk of death during childbirth.[145] A 2008 review of interventions estimated that universal supplementation with calcium, iron, and folic acid during pregnancy could prevent 105,000 maternal deaths (23.6 percent of all maternal deaths).[146]

Frequent pregnancies with short intervals between them and long periods of breastfeeding add an additional nutritional burden.[141]

Educating children

According to the FAO, women are often responsible for preparing food and have the chance to educate their children about beneficial food and health habits, giving mothers another chance to improve the nutrition of their children.[145]

Elderly

Essential nutrients are one of the main requirements of elderly care.

Malnutrition and being underweight are more common in the elderly than in adults of other ages.[147] If elderly people are healthy and active, the aging process alone does not usually cause malnutrition.[148] However, changes in body composition, organ functions, adequate energy intake and ability to eat or access food are associated with aging, and may contribute to malnutrition.[149] Sadness or depression can play a role, causing changes in appetite, digestion, energy level, weight, and well-being.[148] A study on the relationship between malnutrition and other conditions in the elderly found that malnutrition in the elderly can result from gastrointestinal and endocrine system disorders, loss of taste and smell, decreased appetite and inadequate dietary intake.[149] Poor dental health, ill-fitting dentures, or chewing and swallowing problems can make eating difficult.[148] As a result of these factors, malnutrition is seen to develop more easily in the elderly.[150]

Rates of malnutrition tend to increase with age with less than 10 percent of the "young" elderly (up to age 75) malnourished, while 30 to 65 percent of the elderly in home care, long-term care facilities, or acute hospitals are malnourished.[151] Many elderly people require assistance in eating, which may contribute to malnutrition.[150] However, the mortality rate due to undernourishment may be reduced.[152] Because of this, one of the main requirements of elderly care is to provide an adequate diet and all essential nutrients.[153] Providing the different nutrients such as protein and energy keeps even small but consistent weight gain.[152]

In Australia malnutrition or risk of malnutrition occurs in 80 percent of elderly people presented to hospitals for admission.[154] Malnutrition and weight loss can contribute to sarcopenia with loss of lean body mass and muscle function.[147] Abdominal obesity or weight loss coupled with sarcopenia lead to immobility, skeletal disorders, insulin resistance, hypertension, atherosclerosis, and metabolic disorders.[149] A paper from the Journal of the American Dietetic Association noted that routine nutrition screenings represent one way to detect and therefore decrease the prevalence of malnutrition in the elderly.

Welfare economics

From Wikipedia, the free encyclopedia

Welfare economics is a branch of economics that uses microeconomic techniques to evaluate well-being (welfare) at the aggregate (economy-wide) level. A typical methodology begins with the derivation (or assumption) of a social welfare function, which can then be used to rank economically feasible allocations of resources in terms of the social welfare they entail. Such functions typically include measures of economic efficiency and equity, though more recent attempts to quantify social welfare have included a broader range of measures including economic freedom (as in the capability approach).

The field of welfare economics is associated with two fundamental theorems. The first states that given certain assumptions, competitive markets produce (Pareto) efficient outcomes;[2] it captures the logic of Adam Smith's invisible hand.[3] The second states that given further restrictions, any Pareto efficient outcome can be supported as a competitive market equilibrium.[2] Thus a social planner could use a social welfare function to pick the most equitable efficient outcome, then use lump sum transfers followed by competitive trade to bring it about.[2][4] Because of welfare economics' close ties to social choice theory, Arrow's impossibility theorem is sometimes listed as a third fundamental theorem.[5]

Attempting to apply the principles of welfare economics gives rise to the field of public economics, the study of how government might intervene to improve social welfare. Welfare economics also provides the theoretical foundations for particular instruments of public economics, including cost–benefit analysis, while the combination of welfare economics and insights from behavioral economics has led to the creation of a new subfield, behavioral welfare economics.[6]

Measuring social welfare

Cardinal utility

The early Neoclassical approach was developed by Edgeworth, Sidgwick, Marshall, and Pigou. It assumes the following:
  • Utility is cardinal, that is, scale-measurable by observation or judgment.
  • Preferences are exogenously given and stable.
  • Additional consumption provides smaller and smaller increases in utility (diminishing marginal utility).
  • All individuals have interpersonally commensurable utility functions (an assumption that Edgeworth avoided in his Mathematical Psychics).
With these assumptions, it is possible to construct a social welfare function simply by summing all the individual utility functions. Note that such a measure would still be concerned with the distribution of income (distributive efficiency) but not the distribution of final utilities. In normative terms, such authors were writing in the Benthamite tradition.

Ordinal utility

The New Welfare Economics approach is based on the work of Pareto, Hicks, and Kaldor. It explicitly recognizes the differences between the efficiency aspect of the discipline and the distribution aspect and treats them differently. Questions of efficiency are assessed with criteria such as Pareto efficiency and the Kaldor-Hicks compensation tests, while questions of income distribution are covered in social welfare function specification. Further, efficiency dispenses with cardinal measures of utility, replacing it with ordinal utility, which merely ranks commodity bundles (with an indifference-curve map, for example).

Criteria

Efficiency

Situations are considered to have distributive efficiency when goods are distributed to the people who can gain the most utility from them.

Many economists use Pareto efficiency as their efficiency goal. According to this measure of social welfare, a situation is optimal only if no individuals can be made better off without making someone else worse off.

This ideal state of affairs can only come about if four criteria are met:
  • The marginal rates of substitution in consumption are identical for all consumers. This occurs when no consumer can be made better off without making others worse off.
  • The marginal rate of transformation in production is identical for all products. This occurs when it is impossible to increase the production of any good without reducing the production of other goods.
  • The marginal resource cost is equal to the marginal revenue product for all production processes. This takes place when marginal physical product of a factor must be the same for all firms producing a good.
  • The marginal rates of substitution in consumption are equal to the marginal rates of transformation in production, such as where production processes must match consumer wants.
There are a number of conditions that, most economists agree, may lead to inefficiency. They include:
To determine whether an activity is moving the economy towards Pareto efficiency, two compensation tests have been developed. Any change usually makes some people better off while making others worse off, so these tests ask what would happen if the winners were to compensate the losers. Using the Kaldor criterion, an activity will contribute to Pareto optimality if the maximum amount the gainers are prepared to pay is greater than the minimum amount that the losers are prepared to accept. Under the Hicks criterion, an activity will contribute to Pareto optimality if the maximum amount the losers are prepared to offer to the gainers in order to prevent the change is less than the minimum amount the gainers are prepared to accept as a bribe to forgo the change. The Hicks compensation test is from the losers' point of view, while the Kaldor compensation test is from the gainers' point of view. If both conditions are satisfied, both gainers and losers will agree that the proposed activity will move the economy toward Pareto optimality. This is referred to as Kaldor–Hicks efficiency or the Scitovsky criterion.

Equity

There are many combinations of consumer utility, production mixes, and factor input combinations consistent with efficiency. In fact, there are an infinity of consumption and production equilibria that yield Pareto optimal results. There are as many optima as there are points on the aggregate production–possibility frontier. Hence, Pareto efficiency is a necessary, but not a sufficient condition for social welfare. Each Pareto optimum corresponds to a different income distribution in the economy. Some may involve great inequalities of income. So how do we decide which Pareto optimum is most desirable? This decision is made, either tacitly or overtly, when we specify the social welfare function. This function embodies value judgements about interpersonal utility. The social welfare function shows the relative importance of the individuals that comprise society.

A utilitarian welfare function (also called a Benthamite welfare function) sums the utility of each individual in order to obtain society's overall welfare. All people are treated the same, regardless of their initial level of utility. One extra unit of utility for a starving person is not seen to be of any greater value than an extra unit of utility for a millionaire. At the other extreme is the Max-Min, or Rawlsian utility function (Stiglitz, 2000, p102)[incomplete reference]. According to the Max-Min criterion, welfare is maximized when the utility of those society members that have the least is the greatest. No economic activity will increase social welfare unless it improves the position of the society member that is the worst off. Most economists specify social welfare functions that are intermediate between these two extremes.

The social welfare function is typically translated into social indifference curves so that they can be used in the same graphic space as the other functions that they interact with. A utilitarian social indifference curve is linear and downward sloping to the right. The Max-Min social indifference curve takes the shape of two straight lines joined so as they form a 90-degree angle. A social indifference curve drawn from an intermediate social welfare function is a curve that slopes downward to the right.

Social indifference curves small.png

The intermediate form of social indifference curve can be interpreted as showing that as inequality increases, a larger improvement in the utility of relatively rich individuals is needed to compensate for the loss in utility of relatively poor individuals.

A crude social welfare function can be constructed by measuring the subjective dollar value of goods and services distributed to participants in the economy.

Fundamental theorems

The field of welfare economics is associated with two fundamental theorems. The first states that given certain assumptions, competitive markets (price equilibria with transfers, e.g. Walrasian equilibria[3]) produce Pareto efficient outcomes.[2] The assumptions required are generally characterised as "very weak".[7] More specifically, the existence of competitive equilibrium implies both price-taking behaviour and complete markets, but the only additional assumption is the local non-satiation of agents' preferences – that consumers would like, at the margin, to have slightly more of any given good.[3] The first fundamental theorem is said to capture the logic of Adam Smith's invisible hand, though in general there is no reason to suppose that the "best" Pareto efficient point (of which there are a set) will be selected by the market without intervention, only that some such point will be.[3]

The second fundamental theorem states that given further restrictions, any Pareto efficient outcome can be supported as a competitive market equilibrium.[2] These restrictions are stronger than for the first fundamental theorem, with convexity of preferences and production functions a sufficient but not necessary condition.[4][8] A direct consequence of the second theorem is that a benevolent social planner could use a system of lump sum transfers to ensure that the "best" Pareto efficient allocation was supported as a competitive equilibrium for some set of prices.[2][4] More generally, it suggests that redistribution should, if possible, be achieved without affecting prices (which should continue to reflect relative scarcity), thus ensuring that the final (post-trade) result is efficient.[9] Put into practice, such a policy might resemble predistribution.

Because of welfare economics' close ties to social choice theory, Arrow's impossibility theorem is sometimes listed as a third fundamental theorem.[5]

Social welfare maximization

Utility functions can be derived from the points on a contract curve. Numerous utility functions can be derived, one for each point on the production possibility frontier (PQ in the diagram above). A social utility frontier (also called a grand utility frontier) can be obtained from the outer envelope of all these utility functions. Each point on a social utility frontier represents an efficient allocation of an economy's resources; that is, it is a Pareto optimum in factor allocation, in production, in consumption, and in the interaction of production and consumption (supply and demand). In the diagram below, the curve MN is a social utility frontier. Point D corresponds with point C from the earlier diagram. Point D is on the social utility frontier because the marginal rate of substitution at point C is equal to the marginal rate of transformation at point A. Point E corresponds with point B in the previous diagram, and lies inside the social utility frontier (indicating inefficiency) because the MRS at point C is not equal to the MRT at point A.

Social indifference curve diagram.svg

Although all the points on the grand social utility frontier are Pareto efficient, only one point identifies where social welfare is maximized. Such point is called "the point of bliss". This point is Z where the social utility frontier MN is tangent to the highest possible social indifference curve labelled SI.

Criticisms

Some, such as economists in the tradition of the Austrian School, doubt whether a cardinal utility function, or cardinal social welfare function, is of any value. The reason given is that it is difficult to aggregate the utilities of various people that have differing marginal utility of money, such as the wealthy and the poor.

Also, the economists of the Austrian School question the relevance of Pareto optimal allocation considering situations where the framework of means and ends is not perfectly known, since neoclassical theory always assumes that the ends-means framework is perfectly defined.

Some even question the value of ordinal utility functions. They have proposed other means of measuring well-being as an alternative to price indices, willingness to pay functions, and other price-oriented measures.[citation needed] These price-based measures are seen as promoting consumerism and productivism by many.[citation needed] It is possible to do welfare economics without the use of prices; however, this is not always done.

Value assumptions explicit in the social welfare function used and implicit in the efficiency criterion chosen tend to make welfare economics a normative and perhaps subjective field. This can make it controversial.

However, perhaps most significant of all are concerns about the limits of a utilitarian approach to welfare economics. According to this line of argument, utility is not the only thing that matters and so a comprehensive approach to welfare economics should include other factors. The capabilities approach is an attempt to construct a more comprehensive approach to welfare economics, one in which an individual's well-being and agency are evaluated in terms of their capabilities and functionings.

Lie point symmetry

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