The paper studies the political and economic determinants of regional
public transfers. Specifically, it focuses on how such transfers are s
haped by alternative fiscal constitutions, where a constitution is an
allocation of fiscal instruments across different levels of government
s plus a procedure for the collective choice of these instruments. Rea
listic restrictions on fiscal instruments introduce a tradeoff between
risk sharing and redistribution. Different constitutions produce very
different results. In particular, a federal social insurance scheme,
chosen by voting, provides overinsurance, whereas an intergovernmental
transfer scheme, chosen by bargaining, provides underinsurance.