Return to: Search Page or to: Table of Contents Vol. 21, Issue 2

Andrea Ceron, "Brave rebels stay at home: Assessing the effect of intra-party ideological hetrogeneityparty whip roll call on votes" Party Politics, 21 (March 2015), 246-258. [Available at]

First paragraph:

Scholars analyse roll-call votes (RCVs) in order to estimate the policy preferences of individual legislators (MPs) and the ideal point of their respective party. In addition, roll-calls can be adopted to evaluate the degree of heterogeneity and the level of cohesiveness within each parliamentary group insofar as they display the actual voting behaviour of any single MP. The adoption of such measures as a proxy for party cohesion, however, has been criticized for several reasons. Scholars have claimed that RCVs are not an accurate representation of MPs voting behaviour. On the one hand, in fact, votes are recorded on request, and such a request can be made for strategic reasons. On the other, each MP has to choose between casting either a sincere or a strategic vote, and this choice is a function of individual preference (cohesion) and the party whip (discipline). Although such trade-off is an everyday concern for politicians, it becomes more relevant in RCVs when an MP’s choice is observable. In this case the party leadership can observe and decide to punish any deviation from the party line so that representatives can be constrained by either (enforced) party discipline or auto-imposed self-discipline. The pre-emptive power of whipping resources raises the question whether divergent intra-party preferences affect MPs’ voting behaviour in RCVs or, on the contrary, party unity is influenced by internal heterogeneity at all.

Figures and Table

 Table 1: Fractional logit of party unity

Last Paragraph:

With an eye to these results, future research should investigate the interaction between intra-party preferences and whipping tools in a comparative perspective. While factional motions are not that common across countries, these documents are not limited to Italian parties only. Hence, the present analysis has the potential to be replicated for political systems such as those of France, Germany or the UK, where intra-party subgroups (factions, clubs or kreis) publish text documents that express their policy positions on several issues (e.g. Debus and Bräuninger, 2009). Furthermore, given the relevance of the party whip within RCVs, it is worth developing new methods by which to evaluate MPs’ ideological heterogeneity at the individual level through techniques that are less affected by party discipline.

Last updated March 2015