The politics of district design in new PR systems

Abstract This chapter examines our argument, developed in the previous chapter, on district design in newly adopted proportional representation (PR) systems. We expect parties with comparatively concentrated voter bases to try to create high entry barriers for other parties in these regions. Such parties design a large number of districts with low magnitude and oppose mergers with ideologically heterogeneous districts. In contrast, parties with comparatively dispersed voter bases try to reduce entry barriers. Such parties push for large districts that guarantee the proportional translation of votes into seats. By focusing on parties’ influence on district design, this chapter provides empirical evidence to show that geographical variation in partisan support is an important determinant of district magnitude within and across countries. We also demonstrate that parties that influenced the district design continue to benefit from seat-vote distortions in subsequent elections under the new PR system.