Health inequalities in industrial societies

1. Sociology of Industrial Societies Health inequalities in industrial societies Week 1 HT08

2. Health inequalities in industrial societies Lecture plan: Industrialization, health and the demographic transition How are health inequalities related to absolute income? Might health inequalities be more closely linked to relative income in industrial societies? The relative income hypothesis on health: some challenges Health inequalities in industrial societies Week 1 HT08

3. Industrialization, health and the Demographic Transition • 1. Pre-industrialization • High death rate • High birth rate • Stable pop. size • 2. Industrialization • death rate • Stable(ish) birth rate • Rapid pop. growth • 3. Early industrialism • Still death rate • birth rate • Pop. growth slows • 4. Late industrialism • Death rate levels off • Birth rate levels off • Pop. size stabilizes The Demographic Transition in England Crude birth rate Crude death rate Source:Mateos-Planas (2000), p. 5 Health inequalities in industrial societies Week 1 HT08

4. Industrialization, health and the Demographic Transition • Average life expectancy substantially higher in industrialized countries Source: http://www.maps.com/ref_map.aspx?pid=12869 Health inequalities in industrial societies Week 1 HT08

5. How are health inequalities related to absolute income? • At the individual level, higher income means higher life expectancy • At the country level, higher average income means higher life expectancy… • …but relationship strongly curvilinear... • …tailing off after about £25K GDPpc Source: CIA World Factbook Health inequalities in industrial societies Week 1 HT08

6. How are health inequalities related to absolute income? • Focusing on the most industrialized countries… • …practically no association between average income and life expectancy • Undisputed that association holds at individual level • But suggestion that across affluent societies, something other than absolute income also at play Life expectancy and gross national product per capita in the world's 25 richest countries Source: Marmot and Wilkinson (2001) Health inequalities in industrial societies Week 1 HT08

7. Might health inequalities be linked to relative income in industrial societies? • In industrial societies, life expectancy found to be lower in countries with greater income inequality • Taken by many to imply that Norwegians , say, live longer than the British and Americans because they live in a more equitable and egalitarian society Correlation between life expectancy and income inequality among industrialized countries Source: De Vogli et al (2005) See also Wilkinson (1996) Health inequalities in industrial societies Week 1 HT08

8. Might health inequalities be linked to relative income in industrial societies? • Similar relationship found at lower levels of aggregation (US states, Italian regions, Chicago neighbourhoods) • Similar relationship found in relation to other health-related outcomes (stillbirths, infant mortality, homicides, violent crimes) Correlation between Life expectancy and income inequality across US states Source: Kennedy et al (1996) See also Kaplan et al (1996) Health inequalities in industrial societies Week 1 HT08

9. Might health inequalities be linked to relative income in industrial societies? • Relationship between relative income and life expectancy at aggregate levels corresponds to that at individual level • One of most famous examples, the Whitehall Studies by Michael Marmot, found significant associations between Civil Service grade and actual and perceived health, linked to both physiological and social-psychological risk factors Source: Marmot et al (2003) Health inequalities in industrial societies Week 1 HT08

10. Health inequalities linked to relative income? • The relative income hypothesis (see Wilkinson 1990, 1992, 1997, 2001) • Absolute income Relative income • Adequate nutrition, shelter, etc. Relative deprivation • Physiological well-being Psychosocial well-being • Health and life expectancy • In prosperous, industrial societies, relative, not absolute, income is key Health inequalities in industrial societies Week 1 HT08

11. The relative income hypothesis on health: some challenges • Population-level association between income inequality and life expectancy may be at least partly a statistical artefact arising from their non-linear association at the individual level Source: Rodgers 2002 See also Gravelle 1999 Health inequalities in industrial societies Week 1 HT08

12. The relative income hypothesis on health: some challenges • Is mean income an appropriate measure of absolute income at the population level? • Might median or modal income be a better measure, particularly in highly unequal societies? • On a more theoretical level, possibility of ecological fallacy • Can we plausibly infer from aggregated data something about individual responses to income inequality? • Further possibility of spurious correlation • Might other causal factors actually be at play, such as access to health care? Health inequalities in industrial societies Week 1 HT08

13. Health inequalities in industrial societies • Summary • Industrialization undoubtedly linked to improved health at the individual and population levels • In societies at all stages of industrial development, absolute income impacts on health at the individual level • However, studies show practically no association at the population level between mean income and average life expectancy across the most industrialized societies • Instead, income inequality seems to have much more explanatory power • Yet serious challenges to interpretations of population-level associations as indicative of associations at the individual level Health inequalities in industrial societies Week 1 HT08