We provide a new compilation of data on ethnic, linguistic, and religious composition at the subnational level for a large number of countries. Using these data, we measure segregation of groups within the country. To overcome the endogeneity problem that arises because of mobility and endogenous internal borders, we construct an instrument for segregation. We find that more ethnically and linguistically segregated countries, i.e., those where groups live more spatially separately, have a lower quality of government; there is no relationship between religious segregation and governance. Trust is an important channel of influence; it is lower in more segregated countries.

The current study finds that societies which historically engaged in plough agriculture today have lower fertility. We argue, and provide ethnographic evidence, that the finding is explained by the fact that with plough agriculture, children, like women, are relatively less useful in the field. The plough requires strength and eliminates the need for weeding, a task particularly suitable for women and children. This in turn generates a preference for fewer children, lowering fertility.