Why do some federations implement highly progressive intergovernmental transfer schemes while others do not? First, this essay establishes some stylized facts, using provincial-level data from nine federations to measure the extent of inter-regional redistribution achieved through intergovernmental transfers in each country. Second, it explores sources of institutional variation that might help account for these persistent cross-country differences, focusing on theories of legislative bargaining, representation, and the distribution of income across regions. Third, it examines the historical conditions under which the basic institutions of federalism were selected.