1 The Problem of Endogenous Electoral Systems

Electoral systems are commonly treated as exogenous determinants of political party systems, yet understanding remains limited as to how institutions themselves are determined. Addressing this relative lack of attention paid to the origins of electoral systems, I first survey the existing literature to develop a a comprehensive typology of explanations of electoral system change and persistence. I then set forth a theory predicting the conditions under which electoral systems should change, linking motivations for institutional change to instrumentally rational political parties seeking to maximize their legislative seat shares. The theory predicts that electoral laws will change when a coalition of parties exists such that each party in the coalition expects to gain more seats under an alternative electoral institution, and that also has sufficient power to effect this alternative through fiat given the rules for changing electoral laws. To contrast this model to other explanations of electoral system change, I point to its observable implications and outline how it could be confirmed or disconfirmed in empirical research. The comparison also highlights limitations in other approaches to explaining electoral system change, and underscores the importance of institutions in inducing equilibriums in both electoral systems and party systems. 1 The Problem of Endogenous Electoral Systems Electoral systems, states Maurice Duverger, “are strange devices—simultaneously cameras and projectors. They register images which they have partly created themselves” (Duverger 1984, 34). Yet it was originally Duverger’s propositions describing how electoral rules shape a nation’s political party system (1951) that led to the current preoccupation with electoral systems consequences at the expense of the study of their political origins. According to this view, political party systems are shaped by electoral institutions which exert both “mechanical” and “psychological” pressures (Duverger 1951) on voters and parties. The mechanical effect of electoral systems describes how electoral rules constrain the seats that can be awarded from distributions of votes, while the psychological effect deals with the shaping of party and voter strategies in anticipation of the electoral function’s mechanical constraints. Their study has formed the two pillars of a research agenda which according to Riker (1982) in many ways exemplifies the scientific study of politics. Despite the progressive accomplishments in this field, far more emphasis has been paid to the adaptation of parties and candidates to electoral institutions than to the way that electoral institutions themselves are adapted by political parties. Political experience, however, demonstrates repeatedly that while actors do maximize their goals by adapting their strategies to institutions, they also adapt by changing the institutional setting that transforms their strategies into outcomes (Tsebelis 1990). In this field, however, theory has lagged behind empirical analysis, tending to focus on informal examinations of multiple cases (Elster, Offe, and Preuss 1998; Geddes 1996; Lijphart 1992) or inductively generating propositions drawn from single case studies (e.g. Benoit and Schiemann 2001; Ishiyama 1997; Remington and Smith 1996; Bawn 1993; Brady and Mo 1992). What is lacking is a single theory that attempts to reconcile propositions about electoral systems as effects with studies of electoral systems as causes. At the least, such a theory should explore