Causes and Electoral Consequences of Party Policy Shifts in Multiparty Elections: Theoretical Results and Empirical Evidence

The spatial model of elections identifies factors that motivate party elites to shift their policy positions, including changes in voters' policy preferences, rival parties' policy shifts, past election results, and changes in party elites' valence images with respect to dimensions of evaluation such as competence and integrity. I review empirical studies on multiparty elections, i.e., elections involving three or more major parties, that evaluate party elites' policy responses to these factors, along with empirical studies on the electoral consequences of parties' policy shifts. This review reveals a paradox: on the one hand, empirical studies conclude that parties systematically shift their policy positions in response to the factors that spatial modelers have identified. On the other hand, there is only weak and inconsistent empirical evidence that voters actually perceive parties' policy shifts, and/or that these shifts have significant electoral consequences. Thus the predictions of spatial theory are largely verified, whereas the assumptions that underpin spatial theory are called into question.