Ideological congruence and electoral institutions

Although the literature examining the relationship between ideological congruence and electoral rules is quite large, relatively little attention has been paid to how congruence should be conceptualized. As we demonstrate, empirical results regarding ideological congruence can depend on exactly how scholars conceptualize and measure it. In addition to clarifying various aspects of how scholars currently conceptualize congruence, we introduce a new conceptualization and measure of congruence that captures a long tradition in democratic theory emphasizing the ideal of having a legislature that accurately reflects the preferences of the citizenry as a whole. Our new measure is the direct counterpart for congruence of the vote-seat disproportionality measures so heavily used in comparative studies of representation. Using particularly appropriate data from the Comparative Study of Electoral Systems, we find that governments in proportional democracies are not substantively more congruent than those in majoritarian democracies. Proportional democracies are, however, characterized by more representative legislatures.