Figure 20. Growth and Inequality: Per Capita Growth and
Change in Income Inequality in 94 Developing Countries,
1990 -2008 (or latest available)Source: Authors’ calculations using World Bank (2011) and Solt (2009)
5.B. Results in health and social problems
Wilkinson and Pickett (2010) examine the relationship between
income inequality and eleven unique health and social problems.
They carry out empirical tests across a group of OECD countries as
well as the 50 states in the United States. Among both settings, the
results clearly show that health and social outcomes are substantially
worse in more unequal societies. In particular, individuals in more
equal societies, inter alia, enjoy better health, live longer, are less
likely to experience mental illness, perform better in school, use less
illegal drugs, engage in less criminal behaviour, have better social
mobility, are more trusting, experience less violence and are less
likely to be teenage mothers when compared to those living in more
unequal societies.
One of Wilkinson and Pickett’s most significant contributions was
the development of the International Index of Health and Social
Problems (IHSP). The composite index covers 23 OECD countries
and includes the following indicators: homicides, imprisonment,
infant mortality, life expectancy, maths and literacy score, mental
illness, obesity, social mobility, teenage births and trust. To date, the
IHSP offers perhaps the most comprehensive cross-national