chapter 29
...................................................................................................................................................ELECTORAL SYSTEMS
...................................................................................................................................................shaun bowler
This chapter looks at electoral systems and electoral system change from an institu-
tional perspective. As we will see, it is a perspective that lends itself to a rational actor
framework that emphasizes the strategic choices made by voters and political elites. A
central organizing theme of this chapter is the way in which Duverger’s Law can be
taken to be the canonical statement of what electoral systems as institutions do and
why the choice of electoral institutions matters so much. Discussions of electoral
system eVects and consequences can be seen as a generalization of Duverger’s insight
as it applied to single member simple plurality (SMSP) electoral systems. In subse-
quent sections we discuss changes in electoral systems or, more accurately, the
remarkable lack of changes in electoral systems worldwide. Despite many opportun-
ities for change, and a theoretical expectation which suggests parties and candidates
are constantly seeking to change the rules to their advantage, electoral systems rarely,
if ever, change. In some ways, explaining the absence of change is harder than
explaining change itself. We begin, however, by placing electoral systems in the
broader theoretical context of political institutions.
1 Electoral Systems as Political
Institutions
.........................................................................................................................................................................................
‘‘At the most basic level, electoral systems translate the votes cast in [an election]
into seats won by parties and candidates [in the legislature]’’ (IDEA 2002 , 7 ).