Long-term goal.
To estimate the effects of income inequality on social capital and health. A growing concern in public health centers on the harmful effects of income inequality on health. Income inequality erodes social capital-trust, safety nets, and norms of reciprocity that enable people to act collectively to protect health. Pitted against this view is a second one that emphasizes the direct protective role of personal income on health that works independent of income inequality or social capital. To date, most research on income inequality and health has relied on secondary, observational data from adults in large geographic units of developed nations and has produced inconclusive results.
Specific aims.
To obtain more precise estimates of the links between income inequality, social capital, and health, a multidisciplinary team proposes to: 1) do preliminary test of hypotheses, 2) estimate magnitude of attrition, 3) identify adverse effects, and 4) pilot test methods to measures stress, a path by which inequality presumably affects health.
Research design and methods.
Researchers will pilot test the use of an experimental research design that changes parental income and village income inequality in a foraging-farming society of native Amazonians in Bolivia (Tsimane’). Researchers will assess the short-run effects of the intervention on perceived and objective indicators of general child and adult health. Objective indicators include bio-markers (CRP, hemoglobin, blood pressure, cortisol) and anthropometric indices of nutritional status. Lotteries with rice as a prize will be held in 20 villages for 25% of households in the bottom half of the income distribution; 20 villages will serve as controls. In each household, researchers will select at random one of the two household heads to receive the prize. It is hypothesized that lowering income inequality by raising the income of the poor will produce ambiguous effects on social capital and that income transfer to the poor will enhance parental and child health by improving food intake and energy balance, particularly when transfers go to female heads. Surveys will be done twice: during February-April, 2008, before the intervention (September, 2008), and a follow up will take place during February-April, 2009.
Relevance to public health.
Through an experimental research design, the study contributes to a vibrant debate in progress about the relative weight of individual resources, income inequality, and social capital in shaping individual health.
Funding organization.. National Institute of Health.
