A Unified Theory of Party Competition: A Cross-National Analysis Integrating Spatial and Behavioral Factors. By James Adams, Samuel Merill, III, and Bernard Grofman. New York: Cambridge University Press, 2005. 311p. $70.00 cloth, $28.99 paper.

The Logic of Pre-Electoral Coalition Formation. By Sona Nadenichek Golder. Columbus: The Ohio State University Press, 2006. 209p. $49.95.

A Unified Theory of Party Competition “integrates the perspectives of spatial modeling and behavioral research” (p. xvii). It does so by expanding the usual set of assumptions that underlie spatial models, and by accounting for various aspects of voters' electoral behavior. Choices of campaign strategies by party elites, their decisions of what to propose to the voters, are directed toward the same objective as in the tradition growing from Anthony Downs's (1957) An Economic Theory of Democracy—maximization of the vote that they receive in an election. When pursuing this goal, however, parties confront a richer environment of voters' preferences than spatial theorists customarily assume. James Adams, Samuel Merill, and Bernard Grofman take the Downsian criterion—policy distances between the voter and a party—as but one weighted component in the electors' utility functions. Other factors that compel a voter to support a particular party and which the authors include in order to incorporate “the full diversity of measured influences on the vote” (p. 228) are “partisanship, retrospective economic evaluations, and sociodemographic characteristics” (p. 228). Anticipating that the voters will choose with more than just the policy distances in mind, parties find themselves diverging in policy space as they compete for the vote. Thus, a more realistic set of behavioral assumptions with regard to the voters leads to more reasonable predictions for the location of party platforms than the convergence result characteristic of most spatial models. This furthers the authors' objective to improve the quality of the contribution of the spatial modeling literature to our understanding of the rationale behind the ways in which party systems are arranged in the world's democracies.