Health Outcomes and Socio-Economic Status among ... - Index of - IZA

ehaviors, both of which are believed to offer incomplete explanations. These contributions
have emphasized long-term impacts of early childhood or even inter-uterine environmental
factors (Barker, 1997), the cumulative effects of prolonged exposures to individual stressful
events (Seeman et al., 1997), or reactions to macro-societal factors such as rising levels of
income inequality (Wilkinson, 1996).
This view that the principal direction of causation flows almost exclusively from SES to
health has been challenged (Cutler and Lleras-Muney, forthcoming; Lleras-Muney, 2005;
Smith, 1999; Strauss, 1986, 1993; Strauss and Thomas, 1995, 1998, 2008; Thomas and Strauss,
1997, Thomas, 2010). The best evidence is in fact that causation goes in both direction, from
SES to health and health to SES.
Moreover, many omitted variables determine both health measures and SES. A good
example, the subject of much recent research, is health when very young, which appears to
affect health in older ages, but also SES outcomes such as education and incomes as adults, in
particular (Barker,1994; Gluckman and Hanson, 2005 ; Hoddinott et al., 2008; and Maluccio et
al., 2009). The latter two, experimental, studies, document that nutritional supplements given
to children before 3 years of age in Guatemala were associated with more completed schooling
by the time they are adults, as well as higher adult labor force earnings. And yet, recent careful
studies such as Lleras-Muney (2005) have established that the influence of SES on health status
is in part causal.
With these caveats, it is still of much interest to examine the health-SES gradients. As
discussed, these correlations will also indicate the degree of socio-economic inequalities in
health outcomes and their relationships to inequality in SES, education and resources in
7