I am broadly interested in comparative political economy, development, identity politics, and state-building in the developing countries. Much of my research has been concerned with the effects of mobilized identities (national, ethnic, racial) for the formation of public policy. In Race and Regionalism, I analyze the growth of the Tax State in South Africa and Brazil. The two countries share many characteristics: they are both upper-middle-income countries, and highly unequal--both in terms of income and racial status. Divergent constitutional approaches to race (whether or not to grant equal citizenship to blacks) and federalism shaped the organization of politics in the two countries, leading to the development of very different tax systems. My findings are based on extensive field research, large-scale national surveys, macroeconomic data, and various archival and secondary sources. My more recent research has examined the effects of ethnic boundaries on the formulation and implementation of HIV/AIDS policies across developing countries. Case studies of Brazil, South Africa, and India; cross-state analyses within India; cross-country statistical analyses have all supported the central hypothesis that where ethnic differences are well-institutionalized, governments will be less aggressive in implementing policies for a generally stigmatized condition.