It's Parties that Choose Electoral Systems (Or, Duverger's Laws Upside Down)

Abstract

This article presents, discusses and tests the hypothesis that it is the number of parties that can explain the choice of electoral systems, rather than the other way around. Already-existing political parties tend to choose electoral systems that, rather than generate new party systems by themselves, will crystallize, consolidate or reinforce previously existing party configurations. A general model develops the argument and presents the concept of 'behavioral-institutional equilibrium' to account for the relation between electoral systems and party systems. The most comprehensive dataset and test of these notions to date, encompassing 219 elections in 87 countries since the 19th century, are presented. The analysis gives strong support to the hypotheses that political party configurations dominated by a few parties tend to establish majority rule electoral systems, while multi-party systems already existed before the introduction of proportional representation. It also offers the new theoretical proposition that strategic party choice of electoral systems leads to a general trend toward proportional representation over time.

Reconceptualising Electoral Reform

“…The relationships between electoral systems and other aspects of politics such as governability, representation, accountability and participation are equally, if not even more, relevant (Gallagher and Mitchell 2005;Klingemann 2009;Norris 2004;Powell 2000;Shugart 2005). Scholars questioned if proportional representation systems were the cause (Duverger 1954) or the result of multi-party systems (Colomer 2005;Lipson 1964;Rokkan 1970;Shugart 1992). Along similar lines, there was a discussion of the impact of voting system choice and the handling of social conflicts.…”

“…The dominant rational choice theory posits that electoral reform is due to the strategic calculations of elites who choose electoral rules that suit their own ends of maximising gains and/or minimising losses (Benoit 2004;Blais and Shugart 2008;Boix 1999;Colomer 2005;Rahat 2004). Politicians are the key actors, who act rationally, and their aim is to maximise power by enhancing their party's share of seats in the legislature.…”

“…The bulk of the early literature belongs to the first category; it defined and categorised electoral systems, and established their effects on politics. During this pioneering phase, electoral systems were viewed as fixed because of historical and cultural reasons (Colomer 2005;Nohlen 1984;Taagepera and Shugart 1989). Under the second categoryelectoral system as the dependent variable -studies focused on the establishment and original design of different electoral systems, alongside studies explaining the changing of electoral systems.…”

The More Parties, the Greater Policy Stability

“…On the one hand, it simplifies the analysis by focusing on the policy stability effects of the number of political parties in government. Since the relationships between the number of parties and the electoral system and other institutional variables are well established (see, in particular, Colomer, 2005a;Taagepera, 2007), we can adopt this focus for the sake of parsimony. On the other hand, this article offers precise quantitative measurements and a general equation for the relationship under study, beyond the customary result that it works in the expected direction and is statistically significant.…”

How to Operationalize Two-Partyness

“…Indeed, it is "perhaps the most famous theoretical generalization in political science" (Grofman et al, 2009b). Causality may work in the opposite direction too, if a founding body with only two groupings picks the single member plurality (First-Past-The-Post, FPTP) rule, so as to keep out new competitors (Benoit, 2002(Benoit, , 2004Boix, 1999;Colomer, 2005). Hence, Duverger's law can be restated without causal direction: "Seat allocation by FPTP tends to go with two major parties" (Taagepera, 2007: 103).…”