http://www.imf.org/external/pubs/ft/wp/2000/wp0049.pdf

The paper investigates empirically the impact of ethnic heterogeneity on the amount of public spending on health and education and the quality, or "technical efficiency" of spending, While it finds partial evidence for the claim that more heterogeneous societies spend less on public goods, it suggests that heterogeneity significantly affects the efficiency of public expenditure outcomes in terms of social indicators. The results suggest that the impact of heterogeneity on public expenditure outcomes is not just a public choice problem, but also an issue of "technical efficiency."