Health inequalities in industrial societies

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Sociology of Industrial Societies

• Health inequalities in industrial societies

Week 1 HT08
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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
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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
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Industrialization, health and the Demographic
Transition

• Average life expectancy substantially higher in
  industrialized countries

Source http//www.maps.com/ref_map.aspx?pid12869

Health inequalities in industrial societies
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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
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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
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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
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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
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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
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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

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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
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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
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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