The evolution of new party systems: voter learning and electoral systems

How do new party systems evolve over time? This article argues that party system evolution requires the solution of coordination problems that voters face in early elections; this happens through a learning mechanism. Elections reveal information to voters, who update their beliefs about party viability and the distribution of voters’ preferences and adjust their behaviour. The institutional setting, however, strongly conditions the pace of learning. Restrictive electoral systems (single-member district) accelerate learning through the harsh penalties they impose on miscoordination, while permissive ones (proportional representation) prolong it. Testing the argument on a district-level dataset in new democracies provides ample support; voters learn to cast fewer wasted votes over time and this happens faster in single-member district systems. The findings point to a trade-off between consolidation and representation; while party system evolution is facilitated by restrictive electoral systems, the presence of distinct social groups in the political arena is better served by permissive ones.