The Formation of National Party Systems: Federalism and Party Competition in Canada, Great Britain, India and the United States. By Pradeep K. Chhibber and Ken Kollman. Princeton: Princeton University Press. 2004. 272p. $50.00 cloth, $24.95 paper.

The question of the role institutions play in party aggregation has tended to be dominated by discussions of the role and effects of different electoral systems. In a refreshing change from this preoccupation with electoral systems, Pradeep Chhibber and Ken Kollman turn our attention to the impact of federalism, or, more appropriately, the degree of centralization or devolution of power in governmental systems, on the fragmentation of party systems. Their focus is dynamic: They are interested in the formation of national party systems and in how party systems change over time with respect to their extent of nationalization and in relation to the migration of political authority to the center or from the center to states, provinces, or regions. Highly nationalized party systems are ones in which parties receive similar vote shares across different levels of vote aggregation: district, regional, and national. Conversely, in weakly nationalized party systems, parties are differentially competitive across levels.