Analyses of roll call votes in the European parliament (EP) have become more and more sophisticated and have been used to address many important research question. That rather few votes in the EP are roll call votes has been neglected for quite some time. Drawing on a detailed dataset on policy positions (i.e., the DEU dataset) and combining it with information on votes in the EP, the paper proposes tests of a game-theoretical model dealing with the decision to call a roll call as a disciplining device. The empirical evidence supports several implications of this model, highlights, however, also that for some party groups roll call requests are hardly motivated by disciplining considerations.
