THE STABILITY OF REPRESENTATION: A CROSS‐NATIONAL ANALYSIS OF PARTY POLICY DISPERSION

Abstract

A normatively desirable feature of representative government is for the diversity of ideological choices on offer in the party system to reflect the diversity of policy views in the electorate. Building on the work of Ezrow, and relying on Eurobarometer data which suggest that the degree of public opinion diversity is stable over time, the authors analyse how voting systems mediate the diversity of views in parliament, a variable they label party system dispersion. The paper's central question is: to what extent does party system dispersion remain stable over time? Presented are theoretical arguments that party system dispersion will be more stable in countries that feature single‐member district (SMD) voting systems than in proportional representation (PR) systems. Using cross‐national data on 25 countries over 363 elections, the authors present results that support this hypothesis: they find that proportional representation systems are characterised by fluidity in party system dispersion, whereas party system dispersion in SMD countries remains stable from election to election. The implications of the findings are surprising – to the extent that party platforms reflect the diversity of public opinion within an electoral system, the results suggest that SMD systems do a better job at reflecting the diversity of public opinion viewpoints than do PR systems.