Change in parliamentary party systems and policy outcomes: Hunting the core.

This paper shows that change in party systems within parliaments can lead to major change in policy outcomes. Specifically, we show that policy mobility of parties and fluidity in their parliamentary membership can generate or upset the existence of the policy core as well as determine its location. Our analysis applies to the general case of a multiparty parliament. We then follow up with empirical illustrations that conform to the major types of theoretical dynamics in our analysis, where party change that occurred in parliaments was consistent with attempts to manipulate the policy core. [ABSTRACT FROM AUTHOR]