Excess Male Infant Mortality: The Gene-Institution Interactions

Excess male mortality at early ages is an important source of child inequality in most societies. We examine how improvement in the quality of political institutions affects the male survival disadvantage. Using data on twins in combination with a natural experiment on the development of African institutions, we quantify the distinct effects of biology and preconception environment on the infant mortality sex gap and find that these effects are important only in poor institutions. The analysis implies that improved institutions constrain genetic expression and mitigate preconception influences on excess male infant mortality, which is an optimistic finding with pragmatic implications.