Economic globalization and the change of electoral rules

This paper takes up an argument from Ronald Rogowski about the “natural affinity” between trade and an electoral system with proportional representation. We draw on literature on the historical determinants of electoral system choice to advance the general argument that trade integration and PR are related because the adoption of PR helps to secure gains from trade. Our specific model of electoral rule changes in the age of globalization predicts that the likelihood of electoral rule change towards more proportionality increases with levels of trade integration in the world economy. The theoretical model draws on a micro model of the distributive effects of increased economic integration. Because more proportional systems are more credibly able to commit to compensate the losers of globalization processes, there will be increased demand to change the electoral system towards more proportionality under economic circumstances that increase the costs of maintaining a closed economy. In accordance with our model, our empirical tests find a positive association between (a) trade integration and the proportionality of the electoral system, (b) proportionality and social spending, and (c) global integration levels and the probability of electoral rules changes that render voting rules more proportional.