ABSTRACT
It is hard to envisage representative government, save in terms of unified political parties. Legislative voting unity is a precondition for responsible party government. Existing scholarship has focused extensively on explaining patterns of unified party voting within legislatures by references to presidential versus parliamentary forms of government (see, e.g., Bowler et al. 1999; Carey 2007; Tsebelis 2002). Institutions associated with parliamentary systems, such as the vote of confidence mechanism, are said to enhance party voting unity (Huber 1996). Explanations of variation in party voting unity across parliamentary regimes have been limited.
