We examined the relation between infant mortality rates, gross national product, and income distribution. Our findings support the hypothesis that average measures of population health are influenced by the distribution of income within societies.
PIP: This re-assessment study examined the relation between infant mortality rates, gross national product (GNP), and income distribution using high-quality income distribution data from 23 poor countries (per capita GNP US$1000) and 15 richer countries (per capita GNP $1000). Data from 1970 was used to fit the model equation and then validate the model with the two sets of data for 1990. On the basis of model fit, relation between infant mortality rates, GNP per head, and income distribution was nonlinear rates. In the process of validating the model with 1990 data from 26 countries on the GNP per head and the Gini coefficient, predictions for infant mortality rates in 1990 were in close agreement with the true values (r = 0.89 with the Gini coefficient data for 26 countries; and r = 0.91 with the Gini coefficient data for 94 countries). In both models, infant mortality was negatively associated GNP per head, and positively associated with income inequality; these relation were all highly significant. In conclusion, the findings suggest that in poor countries (per capita GNP US$1000) a substantial reduction in infant mortality rate may be possible by decreasing income inequality or increasing GNP per head. In rich countries, reduction of income inequality was likely to be more effective in lowering infant mortality rates than further increases in GNP per head would be.