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Income inequality and population health: A review and explanation of the evidence

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  • Wilkinson, Richard G
  • Pickett, Kate E.

Abstract

Whether or not the scale of a society's income inequality is a determinant of population health is still regarded as a controversial issue. We decided to review the evidence and see if we could find a consistent interpretation of both the positive and negative findings. We identified 168 analyses in 155 papers reporting research findings on the association between income distribution and population health, and classified them according to how far their findings supported the hypothesis that greater income differences are associated with lower standards of population health. Analyses in which all adjusted associations between greater income equality and higher standards of population health were statistically significant and positive were classified as "wholly supportive"; if none were significant and positive they were classified as "unsupportive"; and if some but not all were significant and supportive they were classified as "partially supportive". Of those classified as either wholly supportive or unsupportive, a large majority (70 per cent) suggest that health is less good in societies where income differences are bigger. There were substantial differences in the proportion of supportive findings according to whether inequality was measured in large or small areas. We suggest that the studies of income inequality are more supportive in large areas because in that context income inequality serves as a measure of the scale of social stratification, or how hierarchical a society is. We suggest three explanations for the unsupportive findings reported by a minority of studies. First, many studies measured inequality in areas too small to reflect the scale of social class differences in a society; second, a number of studies controlled for factors which, rather than being genuine confounders, are likely either to mediate between class and health or to be other reflections of the scale of social stratification; and third, the international relationship was temporarily lost (in all but the youngest age groups) during the decade from the mid-1980s when income differences were widening particularly rapidly in a number of countries. We finish by discussing possible objections to our interpretation of the findings.

Suggested Citation

  • Wilkinson, Richard G & Pickett, Kate E., 2006. "Income inequality and population health: A review and explanation of the evidence," Social Science & Medicine, Elsevier, vol. 62(7), pages 1768-1784, April.
  • Handle: RePEc:eee:socmed:v:62:y:2006:i:7:p:1768-1784
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    1. Soobader, Mah-Jabeen & LeClere, Felicia B., 1999. "Aggregation and the measurement of income inequality: effects on morbidity," Social Science & Medicine, Elsevier, vol. 48(6), pages 733-744, March.
    2. Angus Deaton, 2003. "Health, Inequality, and Economic Development," Journal of Economic Literature, American Economic Association, vol. 41(1), pages 113-158, March.
    3. Franzini, Luisa & Spears, William, 2003. "Contributions of social context to inequalities in years of life lost to heart disease in Texas, USA," Social Science & Medicine, Elsevier, vol. 57(10), pages 1847-1861, November.
    4. Macinko, James A. & Shi, Leiyu & Starfield, Barbara, 2004. "Wage inequality, the health system, and infant mortality in wealthy industrialized countries, 1970-1996," Social Science & Medicine, Elsevier, vol. 58(2), pages 279-292, January.
    5. Lopez, Russ, 2004. "Income inequality and self-rated health in US metropolitan areas: A multi-level analysis," Social Science & Medicine, Elsevier, vol. 59(12), pages 2409-2419, December.
    6. Pattussi, Marcos Pascoal & Marcenes, Wagner & Croucher, Ray & Sheiham, Aubrey, 2001. "Social deprivation, income inequality, social cohesion and dental caries in Brazilian school children," Social Science & Medicine, Elsevier, vol. 53(7), pages 915-925, October.
    7. repec:aph:ajpbhl:2001:91:8:1246-1250_3 is not listed on IDEAS
    8. Singh-Manoux, Archana & Adler, Nancy E. & Marmot, Michael G., 2003. "Subjective social status: its determinants and its association with measures of ill-health in the Whitehall II study," Social Science & Medicine, Elsevier, vol. 56(6), pages 1321-1333, March.
    9. repec:aph:ajpbhl:2001:91:1:99-104_7 is not listed on IDEAS
    10. repec:aph:ajpbhl:2000:90:12:1892-1897_6 is not listed on IDEAS
    11. repec:aph:ajpbhl:1997:87:9:1491-1498_6 is not listed on IDEAS
    12. Szwarcwald, Célia Landmann & Andrade, Carla Lourenço Tavares de & Bastos, Francisco Inácio, 2002. "Income inequality, residential poverty clustering and infant mortality: a study in Rio de Janeiro, Brazil," Social Science & Medicine, Elsevier, vol. 55(12), pages 2083-2092, December.
    13. Robert J. Waldmann, 1992. "Income Distribution and Infant Mortality," The Quarterly Journal of Economics, Oxford University Press, vol. 107(4), pages 1283-1302.
    14. Veenstra, Gerry, 2002. "Social capital and health (plus wealth, income inequality and regional health governance)," Social Science & Medicine, Elsevier, vol. 54(6), pages 849-868, March.
    15. Deaton, Angus & Lubotsky, Darren, 2003. "Mortality, inequality and race in American cities and states," Social Science & Medicine, Elsevier, vol. 56(6), pages 1139-1153, March.
    16. repec:aph:ajpbhl:1999:89:6:845-850_0 is not listed on IDEAS
    17. Fajnzylber, Pablo & Lederman, Daniel & Loayza, Norman, 2002. "Inequality and Violent Crime," Journal of Law and Economics, University of Chicago Press, vol. 45(1), pages 1-40, April.
    18. Fred Pampel & Vijayan Pillai, 1986. "Patterns and determinants of infant mortality in developed nations, 1950–1975," Demography, Springer;Population Association of America (PAA), vol. 23(4), pages 525-542, November.
    19. Gravelle, Hugh & Wildman, John & Sutton, Matthew, 2002. "Income, income inequality and health: what can we learn from aggregate data?," Social Science & Medicine, Elsevier, vol. 54(4), pages 577-589, February.
    20. Kennedy, Bruce P. & Kawachi, Ichiro & Prothrow-Stith, Deborah & Lochner, Kimberly & Gupta, Vanita, 1998. "Social capital, income inequality, and firearm violent crime," Social Science & Medicine, Elsevier, vol. 47(1), pages 7-17, July.
    21. Norman Weatherby & Charles Nam & Larry Isaac, 1983. "Development, inequality, health care, and mortality at the older ages: a cross-national analysis," Demography, Springer;Population Association of America (PAA), vol. 20(1), pages 27-43, February.
    22. Robert, Stephanie A. & Reither, Eric N., 2004. "A multilevel analysis of race, community disadvantage, and body mass index among adults in the US," Social Science & Medicine, Elsevier, vol. 59(12), pages 2421-2434, December.
    23. Regidor, Enrique & Calle, M. Elisa & Navarro, Pedro & Domínguez, Vicente, 2003. "Trends in the association between average income, poverty and income inequality and life expectancy in Spain," Social Science & Medicine, Elsevier, vol. 56(5), pages 961-971, March.
    24. Mayer, Susan E. & Sarin, Ankur, 2005. "Some mechanisms linking economic inequality and infant mortality," Social Science & Medicine, Elsevier, vol. 60(3), pages 439-455, February.
    25. Lorant, Vincent & Thomas, Isabelle & Deliège, Denise & Tonglet, René, 2001. "Deprivation and mortality: the implications of spatial autocorrelation for health resources allocation," Social Science & Medicine, Elsevier, vol. 53(12), pages 1711-1719, December.
    26. Gold, R. & Connell, Frederick A. & Heagerty, Patrick & Bezruchka, Stephen & Davis, Robert & Cawthon, Mary Lawrence, 2004. "Income inequality and pregnancy spacing," Social Science & Medicine, Elsevier, vol. 59(6), pages 1117-1126, September.
    27. John Wildman & Hugh Gravelle & Matthew Sutton, 2003. "Health and income inequality: attempting to avoid the aggregation problem," Applied Economics, Taylor & Francis Journals, vol. 35(9), pages 999-1004.
    28. repec:aph:ajpbhl:2002:92:1:99-104_9 is not listed on IDEAS
    29. Wen, Ming & Browning, Christopher R. & Cagney, Kathleen A., 2003. "Poverty, affluence, and income inequality: neighborhood economic structure and its implications for health," Social Science & Medicine, Elsevier, vol. 57(5), pages 843-860, September.
    30. Laporte, Audrey, 2002. "A note on the use of a single inequality index in testing the effect of income distribution on mortality," Social Science & Medicine, Elsevier, vol. 55(9), pages 1561-1570, November.
    31. Kahn, Henry S. & Tatham, Lilith M. & Pamuk, Elsie R. & Heath, Clark W., 1998. "Are geographic regions with high income inequality associated with risk of abdominal weight gain?," Social Science & Medicine, Elsevier, vol. 47(1), pages 1-6, July.
    32. Diez-Roux, Ana V. & Link, Bruce G. & Northridge, Mary E., 2000. "A multilevel analysis of income inequality and cardiovascular disease risk factors," Social Science & Medicine, Elsevier, vol. 50(5), pages 673-687, March.
    33. Hou, Feng & Myles, John, 2005. "Neighbourhood inequality, neighbourhood affluence and population health," Social Science & Medicine, Elsevier, vol. 60(7), pages 1557-1569, April.
    34. repec:aph:ajpbhl:1998:88:7:1074-1080_3 is not listed on IDEAS
    35. Laporte, Audrey & Ferguson, Brian S., 2003. "Income inequality and mortality: time series evidence from Canada," Health Policy, Elsevier, vol. 66(1), pages 107-117, October.
    36. Reagan, Patricia B. & Salsberry, Pamela J., 2005. "Race and ethnic differences in determinants of preterm birth in the USA: broadening the social context," Social Science & Medicine, Elsevier, vol. 60(10), pages 2217-2228, May.
    37. Henderson, Claire & Liu, Xinhua & Diez Roux, Ana V. & Link, Bruce G. & Hasin, Deborah, 2004. "The effects of US state income inequality and alcohol policies on symptoms of depression and alcohol dependence," Social Science & Medicine, Elsevier, vol. 58(3), pages 565-575, February.
    38. Blakely, Tony A. & Lochner, Kimberly & Kawachi, Ichiro, 2002. "Metropolitan area income inequality and self-rated health--a multi-level study," Social Science & Medicine, Elsevier, vol. 54(1), pages 65-77, January.
    39. Subramanian, S. V. & Kawachi, Ichiro & Kennedy, Bruce P., 2001. "Does the state you live in make a difference? Multilevel analysis of self-rated health in the US," Social Science & Medicine, Elsevier, vol. 53(1), pages 9-19, July.
    40. Larrea, Carlos & Kawachi, Ichiro, 2005. "Does economic inequality affect child malnutrition? The case of Ecuador," Social Science & Medicine, Elsevier, vol. 60(1), pages 165-178, January.
    41. Kawachi, Ichiro & Kennedy, Bruce P., 1997. "The relationship of income inequality to mortality: Does the choice of indicator matter?," Social Science & Medicine, Elsevier, vol. 45(7), pages 1121-1127, October.
    42. repec:aph:ajpbhl:2003:93:8:1294-1296_9 is not listed on IDEAS
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