Income inequality and health: importance of a cross-country perspective

This paper uses a unique dataset-containing information collected in 2006 on individuals aged 40-79 in 21 countries throughout the world to examine whether individual income, relative income in a reference group, and income inequality are related to health status across middle/low and high-income countries. The dependent variable is self-assessed health (SAH), and as a robustness check, activities of daily living (ADL) are considered. The focus is particularly on assumptions regarding an individual's reference group and how the estimated relationships depend on the level of economic development. Correcting for national differences in health reporting behavior, individual absolute income is found to be positively related to individual health. Furthermore, in the high-income sample, there is strong evidence that average income within a peer-age group is negatively related to health, thus supporting the relative income hypothesis. In middle/low-income countries, it is instead average regional income that is negatively associated with health. Finally, there is evidence of a negative relationship between income inequality and individual health in high-income countries. Overall, the results suggest that there might be important differences in these relationships between high-income and middle/low-income countries.