Abstract
While it has long been observed in western Europe that deputies from the same party caucus generally take identical positions when legislative votes are taken, the explanation for this commonly occurring party voting agreement is controversial. The sociological approach argues that MPs hold together for normative reasons while the institutionalist tradition argues that discipline emerges as rational actors discover self-interested reasons to vote en bloc. The creation of democratic state legislatures in post-communist eastern Germany provides an opportunity to investigate the origins of party voting agreement. There, institutions conducive to high party voting agreement were extended to a region where political elites did not share norms conducive to party cohesion. This article examines the development of legislative voting in eastern Germany between 1990 and 2000. The examination shows that, while antiparty sentiment may have initially complicated the task of developing cohesive parliamentary parties, over the past decade institutional incentives have created high levels of party voting akin to those in western Germany.