Health inequality/Socioeconomic status and health
For at least 30 years, it has been recognized that poor people have poor health and that their poverty is not because of their poor health. Health inequalities is the term used in the United Kingdom and Europe for this observation. In the U.S., it is called socioeocomic status and health. More attention has been paid to these effects since the publication in England of the Black Report in 1980 and the Acheson Report in 1998. In most public health studies, however, the effects of social class or socioeconomic status on health are statistically controlled, and this prevents looking at them and their causes.
The reasons for the association between health and poverty are elusive, and not explained by differences in behavioral risk factors such as smoking or relative weight, or even by access to medical care. The range of income distribution, or relative deprivation, is probably a key factor in producing this disparity.
Looking into the distant past provides insight as well. Primitive societies
were sharing, caring societies with remarkable health outcomes. Scientific
studies show that with the "progress" of domesticating plants and animals
to live under agricultural systems, health declined. That such "progress" produced
hierarchies may be an important downstream effect that continues to this day.
1. van Doorslaer E, Wagstaff A, Bleichrodt H, et al. (1997). Income-related inequalities in health: Some international comparisons. Journal of Health Economics. 16(1):93-112.
2. Kawachi I, Kennedy BP, Gupta V, Prothrow SD. (1999). Women's status and the health of women and men: a view from the States. Soc Sci Med. 48(1):21-32.
3. Haan M, Kaplan GA, Camacho T. ( 1987). Poverty and health: prospective evidence from the Alameda County Study. American Journal of Epidemiology. 125: 989-98.
4. Wilkinson RG. (1994) "Health, redistribution and growth." In: Paying
for inequality: the economic cost of social injustice. Edited by A. Glyn
and D. Miliband. London: Rivers Oram Press.
5. Wilkinson RG. (1997). Health inequalities: relative or absolute material standards? British Medical Journal. 314:591-5
6. Steckel RH. (1994). "Heights and health in the United States." In: Stature,
living standards and economic development. Edited by J. Komlos. Chicago:
University of Chicago Press.
7. Blakely, T., Kennedy, P., Kawachi, I., Socioeconomic inequality in voting participation and self-rated health. American Journal of Public Health, January 2001, Vol 91, No. 1.
General materials on social determinants of health
The health status of a population is strongly
influenced by the nature of its social relations, considered very
generally. We can consider
these relations in many ways: social class, economic status, social
networks, political systems, social stress, poverty, and environmental
relations. It all comes down to the ways in which the rules governing
relations in a society are constructed.
1. Berkman, L.F. & Kawachi, Editors, Social Epidemilogy. I. (2000).
Oxford University Press.
2. Marmot, M. (2003). "Understanding Social Inequalities in Health." Perspectives
in Biology and Medicine 46(3 Supplement): S9-S23.
3. Kawachi, I. and B. P. Kennedy (2002). The Health of Nations: Why Inequality Is Harmful to Your Health. New York, New Press.
4. Marmot M, Wilkinson RG, eds. (1999). Social Determinants of Health. Oxford: Oxford University Press.
5. Tarlov, A. R. & R. F. St. Peter, Eds. (2000). The Society and Population
Health Reader, Volume II: a state and community perspective. New York,
6. Wilkinson RG. (1996). Unhealthy Societies: the afflictions of inequality. London: Routledge.
7. Wilkinson R, Marmot M, eds. (1998). Social Determinants of Health: The Solid Facts. Copenhagen: World Health Organization Regional Office for Europe.
8. Wilkinson, R. (2001). Mind the gap: Hierarchies, Health and Human Evolution. New Haven, Yale University Press.
Overviews, reviews on hierarchy
These scientific papers and books present an overview of factors that affect the health of a population, concentrating on hierarchy, which is perhaps the most significant factor when considering health as measured by life expectancy or infant mortality. To date, measures of hierarchy concentrate on income distribution because this statistic is available, estimates relative deprivation to some extent and is related to psychosocial variables likely to impact on health. Many studies within populations find socioeconomic or psychosocial factors strongly affect health, making income distribution a reasonable measure to use in beginning to look at what affects a population's health. The book Unhealthy Societies is the best place to begin further study. Mind the Gap is a brief look at psychosocial factors at work in communities that have strong health effects.
1. Deaton, A. (2002). Policy Implications of the Gradient of Health and Wealth:
An economist asks, Would redistributing income improve population health?Health
Affairs 21(2): 13-26.
2. Marmot, M. (2002). The Infuence of Income on Health: Views of An Epidemiologist:
Does money really matter? Or is it a marker for something else?Health
Affairs 21(2): 31-46.
3. Kawachi I, Kennedy BP, Wilkinson RG, eds. (1999). The Society and Population Health Reader, Volume I: Income Inequality and Health. New York: New Press.
4. Wilkinson RG. (1994). Unfair Shares: the effects of widening income differentials on the welfare of the young. London: Barnardos.
5. Wilkinson RG. (1994) The epidemiological transition: from material scarcity to social disadvantage?In: Daedalus. (Journal of the American Academy of Arts and Sciences). 123 (4):61-77
6. Kawachi I, Levine S, Miller M, Lasch K, Amick III B. (1994). Income inequality and life expectancy - theory, research, and policy. Society and Health Working Paper Series No. 94-2; Boston: Harvard School of Public Health.
Income inequality and health: within country comparisons
These papers were the first to demonstrate the association between income inequality and various measures of health within divisions of a country. They overcome the difficulties of finding consistent data among countries.
The strongest effect of income inequality on adverse health in populations has been demonstrated by many studies concerning the United States of America. Results have not been entirely consistent, and economists and some public health researchers disagree about the interpretation of those results.
In highly monetized societies such as the USA, where almost everything that individuals and families need is purchased, income and its distribution seem to be a reasonable measure of hierarchy. In Western European countries with their social democracies, in contrast, many behind-the-scenes supports (such as health care, education, housing, transportation, and child care) do not depend on having an income. Even in such nations, however, social class remains the most important determinant of health outcomes in populations. Because of the social supports in Western Europe, income distribution may not be the best measure of class, and researchers have not yet found a substitute statistic that captures this idea.
1. Lynch JW, Kaplan GA, Pamuk ER, et al. (1998) Income inequality and mortality
in metropolitan areas of the United States.Am J Public Health.
2. Soobader, M. J. and F. B. LeClere (1999). Aggregation and the measurement
of income inequality. effects on morbidity.Social Science and Medicine. 48(6): 733-44.
3. Kennedy BP, Kawachi I, Glass R, Prothrow SD. (1998) Income distribution,
socioeconomic status, and self rated health in the United States: multilevel
analysis.British Medical Journal.. 317(7163):917-21
4. Kaplan GA, Pamuk E, Lynch JW, Cohen RD, Balfour JL. ( 1996). Inequality
in income and mortality in the United States: analysis of mortality and potential
pathways.British Medical Journal.. 312: 999-1003
5. Kaplan GA. (1996). Correction: Inequality in income and mortality in the
United States: analysis of mortality and potential pathways.British Medical Journal. 312: 1253
6. Kennedy BP, Kawachi I, Prothrow-Stith D. (1996). Income distribution and mortality: cross sectional ecological study of the Robin Hood index in the United States. British Medical Journal. 312: 1004-7.
7. Kennedy BP, Kawachi I, Prothrow-Stith D. (1996) Important correction. Income
distribution and mortality: cross sectional ecological study of the Robin Hood
index in the United States.British Medical Journal. 312: 1194
8. Kawachi I, Kennedy BP. (1997). The relationship of income inequality to
mortality - does the choice of indicator matter? Social Science & Medicine. 45:
9. Ben-Shlomo Y, White IR, Marmot M. (1996). “Does the variation in the socioeconomic characteristics of an area affect mortality?” British Medical Journal. 312: 1013-4
10. Blakely, T., Lochner, K., Kawachi, I. “Metropolitan area income inequality
and self-rated health- a multi-level study.” Soc Sci & Med. 54 (2002)
11. Brodish, Paul, H., Massing, M., Tyroler, H., Income inequality and all-cause mortality in the 100 counties of North Carolina, Southern Medical Journal, Vol 93, No 4, April 2000 386-391
12. Franzini, Luisa, Ribble, J., Spears, W. (2001). “The effects of income inequality and income level on mortality vary by population size in Texas counties.” Journal of Health and Social Behavior. Vol 42, No 4, pp 373-383.
13. McLaughlin, Diane and C. Shannon Stokes. Income inequality and mortality
in US counties: Does minority racial concentration matter? American Journal of Public Health. January 2002, Vol 92, No. 1. 99-104
These papers discuss the studies that first demonstrated the association between income inequality and various measures of health in countries. They are published in public health, medical, or economics journals. Most of them require some familiarity of epidemiology.
1. Wilkinson RG. ( 1992). Income distribution and life expectancy. British Medical Journal.304: 165-8.
2. McIsaac SJ, Wilkinson RG. (1997). Income distribution and cause-specific
mortality.European Journal of Public Health. 7: 45-53
3. Rodgers GB. (1979) Income and inequality as determinants of mortality:
an international cross-sectional analysis. Population Studies.. 33:
4. Ross, Nancy, A., Wolfson, M.C., Dunn, J.R., Berthelot, J-M., Kaplan, G.A.,
Lynch, J.W. Relation between income inequality and mortality in Canada and
in the United States: Cross sectional assessment using census data and vital
statistics.British Medical Journal Vol. 320, April 2000.
Relative deprivation and social problems, especially violence and homicide,
and social cohesion
Hierarchy—the range between the haves and have nots, or relative deprivation, in a population—appears to be associated with many social factors. These papers demonstrate some of the factors related to violence, which are linked with measures of community cohesion. Studies support the key position of hierarchy, measured by income inequality as related to homicide across nations, within nations, and in metropolitan areas as well as in cities. There is an extensive literature on this in the criminology and sociology literature; only a few of the studies are listed.
1. Kennedy BP, Kawachi I, Prothrow SD, Lochner K, Gupta V. (1998). Social capital, income inequality, and firearm violent crime. Social Science and Medicine. 47(1):7-17
2. Kawachi I, Kennedy BP, Lochner K, Prothrow-Stith D. (1997). Social capital, income inequality and mortality. American Journal of Public Health. 87: 1491-8
3. Gilligan J. (1996) Violence: Our Deadly Epidemic and its Causes. New York: G.P. Putnam.
4. James O. (1995). Juvenile violence in a winner-looser culture. London: Free Association Books.
5. Hsieh CC, Pugh MD. (1993). Poverty, income inequality, and violent crime: a meta-analysis of recent aggregate data studies. Criminal Justice Review. 18:182-202.
6. Wilson M, Daly M. (1997). Life expectancy, economic inequality, homicide, and reproductive timing in Chicago neighbourhoods. British Medical Journal. 314: 1271-4.
7. Sampson RJ, Raudenbush SW, Earls F. (1997). Neighborhoods and violent crime: a multilevel study of collective efficacy. Science. 277: 918-924
8. Blau J, Blau P. The costs of inequality: metropolitan structure and
violent crime. American
9. Krohn MD. (1976). Inequality, unemployment and crime: A Cross-National Analysis. Sociological Quarterly. 17: 303-13
10. Crutchfield R. (1989) Labor stratification and violent crime. Social Forces. 68: 489-512
11. Braithwaite J, Braithwaite V. The effect of income inequality and social democracy on homicide. British Journal of Criminology 1980; 20 (1): 45-53
12. Krahn H, Hartnagel TF, Gartrell JW. (1986) Income inequality and homicide rates: cross-national data and criminological theories. Criminology. 24: 269-295
13. Wilkinson RG. (1997). Income, inequality and social cohesion. American Journal of Public Health. 1504-6.
Egalitarianism sees equality of condition, outcome, reward, and privilege
as a key goal in how a society is organized. Societies that share resources
have caring social relationships that are considerably different from those
that discourage sharing and in which power relationships elevate some to great
1. Kluegel, J.R. and Smith, E.R. (1986). Beliefs About Inequality: Americans’ Views of What Is and What Ought to Be. Aldine de Gruyter.
2. Boehm, C. (1999). Hierarchy in the Forest: The Evolution of Egalitarian Behavior. Cambridge, Harvard University Press.
3. Cohen, M. N. (1991). Health and the Rise of Civilization. New Haven, Yale University Press.
4. Cohen, M. N. (1998). The emergence of health and social inequalities in the archaeological record. Human Biology and Social Inequality: 39th Symposium Volume of the Society for the Study of Human Biology. S. S. Strickland and P. S. Shetty. Cambridge, Cambridge University Press: 249-271.
5. Erdal, D. and A. Whiten (1996). "Egalitarianism and Machiavellian Intelligence in Human Evolution." In Modelling the Early Human Mind. P. Mellars and K. Gibson. Cambridge, UK, McDonald Institute for Archaeological Research: 139-160.
6. Larsen, C. S. (1995). Biological changes in human populations with agriculture.Annual Review of Anthropology. 24: 185-213.
7. Steckel, R. H. (1995). Stature and the Standard of Living.Journal of Economic Literature. 33: 1903-1940.
Psychosocial conditions and health
These papers, dealing with hopelessness, social networks, relative hierarchy, and family conflict, shed light on the aspects of social hierarchy that are measured by income distribution and have health effects.
1. Kawachi I, Colditz GA, Ascherio A, Rimm EB, Giovannucci E, Stamfer MF, Willett WC. A Prospective study of social networks in relation to total mortality and cardiovascular disease in men in the USA. (1996). Journal of Epidemiology and Community Health. 50: 245-251.
2. Montgomery SM, Bartley MJ, Wilkinson RG. (1997). Family conflict and slow growth. Archives of the Diseases of Childhood. 77: 326-30.
3. Singh-Manoux, A., Adler, N., Marmot, M. (2003) Subjective social status:
its determinants and its association with measures of ill-health in the Whitehall
II study, Social
Science & Medicine 56: 1321-1333.
Biological mechanisms to explain the hierarchy/health relationship
How does hierarchy or income inequality in a population translate into mechanisms that affect a population's health? These publications, looking mostly at primate populations, begin to tackle this question.
Considered simply, chronic stress is produced in a hierarchy, with those toward the bottom having more stress. the level of stress is indicated by higher levels of the hormone cortisol, the chronic-stress hormone. Although the relationship between hierarchy and stress has mostly been studied in non-human primates, mechanisms there most likely apply to humans, as well.
Studies in primate populations range from those conducted by observation in the field, with occasional sampling of blood and measurement of parameters on anesthetized animals, as well as studies in captivity, where many aspects of the environment are controlled and manipulated in the experimental design. The effects of hierarchy may have their most important and long-lasting effects in early childhood.
1. Keating DP, Hertzman C, eds. (1999) Developmental Health and the Wealth of Nations: Social, biological and educational dynamics. New York: Guildford Press.
2. Sapolsky RM. (1993 ). Endocrinology alfresco: psychoendocrine studies of wild baboons. Recent Progress in Hormone Research. 48: 437-68.
3. Shively CA, Clarkson TB. (1994). Social status and coronary artery atherosclerosis in female monkeys. Arteriosclerosis and Thrombosis. 14: 721-6.
4. Adler, N. E., M. Marmot, et al., Eds. (1999). Socioeconomic Status and Health in Industrial Nations: Social, Psychological, and Biological Pathways. Ann N. Y. Acad. Sci. New York, New York Academy of Sciences. Volume 896.
5. McEwen, B. S. and E. N. Lasley (2002). The End of Stress as We Know It. Washington, DC, Jospeh Henry Press.
6. Shively, C. A. (2000). Social status, stress, and health in female monkeys. The Society and Population Health Reader, Volume II: a state and community perspective. A. R. Tarlov and R. F. St. Peter. New York, New Press: 278-289.
7. Stansfeld, S. and M. Marmot, Eds. (2002). Stress and the Heart: Psychosocial Pathways to Coronary Heart Disease. London, BMJ Books.
8. Shively CA, Laird KL, Anton RF. (1997). The behavior and physiology of social stress and depression in female cynomolgus monkeys. Biological Psychiatry. 41: 871-82
9. Sapolsky RM, Share LJ. (1994). Rank-related differences in cardiovascular function among wild baboons: role of sensitivity to Glucocorticoids. American Journal of Primatology. 32: 261-75.
10. Kristenson, M., K. Orth-GomZr, et al. (1998). Attenuated Cortisol Response to a Standardized Stress Test in Lithuanian Versus Swedish Men: The LiVicordia Study. International Journal of Behavioral Medicine. 5(1): 17-30.
Criticisms of the hierarchy/health relationship
The criticisms of the hypothesis that our health as a population is related to structural factors that determine the range of hierarchy or status differences between the rich and poor, to date, fall generally into two domains. One, put forth mostly by economists, focuses on the limitations of income distribution as a measure of hierarchy. The other questions whether relative deprivation works by limiting what the lower classes can obtain or purchase to produce health or whether it is the psychosocial nature of human relationships in societies that matters more. Another smaller set of criticisms relates to how to treat the non-biological concept of race, as present in the US.
Any issue can be trivialized by saying that there are many causes or elements that are important, but this makes addressing the key or primordial factors less likely to happen. Therefore we prefer to focus on the most basic rules of society that govern how the fruits of society are apportioned and the health affect of those rules.
1. Judge K, Mulligan J-A, Benzeval M. (1998). Income inequality and population health. Soc Sci Med. 199846:567-79.
2. Wilkinson, R.G. (1998). Letter to the Editor. Soc Sci Med.47(3):411-12.
3. Judge K, Mulligan JA, Benzeval M. (1998). Reply to Richard Wilkinson. Soc Sci Med. 46(7):983-85.
4. Gravelle H. (1998). How much of the relation between population mortality and unequal distribution of income is a statistical artefact? BMJ. 316(31 January 1998):382-5
5. Wilkinson RG. (1998). Mortality and distribution of income. Low relative income affects mortality [letter; comment]. BMJ. 316(7144):1611-2
6. Wolfson M, Kaplan G, Lynch J, Ross N, Backlund E. (1999). Relation between income inequality and mortality: empirical demonstration. BMJ. 319(7215):953-7.
7. Gravelle H. (1999). Diminishing returns to aggregate level studies. BMJ. 319(7215):955-6
8. Bezruchka, S. (2002). Hierarchy and health are related. BMJ 324(7343): 978.
9. Mackenbach, J. P. (2002). Income inequality and population health: Evidence favouring a negative correlation between income inequaltiy and life expectancy has disappeared. BMJ. 324(7328): 1-2.
10. Wilkinson, R. (2002). Better measures of social differentiation and hierarchy are needed. BMJ. 324(7343): 978.
11. Judge K. (1995). Income distribution and life expectancy: a critical appraisal. British Medical Journal. 311: 1282-5.
12. Lynch, J. and G. Davey Smith (2003). Rates and states: reflections on the health of nations. Int. J. Epidemiol. 32(4): 663-670.
13. Deaton, Angus, Health, inequality, and economic development. Journal of Economic Literature. Vol. XLI, March 2003. 113-158.
14. Kawachi, I, and T. Blakely. Commentary; When economists and epidemilogists disagree. Journal of Health Politics, Policy and Law. Vol 26, No. 3, June 2001.
15. Mellor, J. and J. Milyo, Reexamining the evidence of an ecological association between income inequality and health. Journal of Health Politics, Policy and Law. Vol 26, No. 3, June 2001.
16. Wagstaff, A. and Van Doorslaer, E. (2000). Income inequality and health: What does the literature tell us? Annual Rev. Public Health. 21, 543-67.
Research and measurement techniques
We could add some stuff here on different ways to measure hierarchy including the gini index, robin hood, etc. JY: also need an intro. Jen, I emailed her asking for the intro material.
1. Atkinson, A.B. and F. Bourguignon. (2000). Handbook of income distribution, Volume 1. Elsevier.
2. Pan American Health Organization (PAHO), World Health Organization. Measuring health inequalities: Gini coefficient and concentration index. http://www.paho.org/English/SHA/be_v22n1-Gini.htm.
Preston, S. The changing relation between mortality and level of economic development Population Studies. Volume 29, Issue 2 (July 1975), 231-248.
3. Blakely, T. and I. Kawachi. (2001) What is the difference between controlling for mean versus median income in analyses of income inequality? J. Epidemiol Community Health. 55: 352-353.
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