Party System Fragmentation and the Demand for Electoral Reform

• In Event: Demands and Impact of Electoral Reforms

Abstract

Scholars have long debated whether party system size is a cause or consequence of the adoption of proportional representation. Much of this literature has focused on the elite level politics of electoral reform, I examine a neglected aspect of this debate – citizen demand for electoral reform – drawing on aggregate and survey evidence from Great Britain. Aggregate level evidence from the 2011 referendum on the adoption of the Alternative Vote, and a 2016-17 parliamentary petition in favour of Proportional Representation, shows that support for electoral reform within the UK is correlated with the fragmentation of the party system at the constituency level. Using a combination of cross-sectional and panel survey evidence from the 2011 referendum and 2015 election, I then show that this aggregate relationship can be explained by the number of people who vote for losing candidates in their parliamentary constituency, which is higher in more fragmented constituencies. Using a regression discontinuity design, I estimate the causal effect of voting for a losing candidate on subsequent support for electoral reform, and show the people who vote for losing candidates are more likely to support reforming the electoral system.

Author

• Christopher Prosser, University of Manchester