Electoral Systems, Voters' Interests and Geographic Dispersion

There is general agreement that democratic institutions shape politicians' incentives to cater to certain constituencies, but which electoral system causes politicians to be most responsive to narrow interests is still debateable. Some argue that plurality electoral rules provide the greatest incentives for politicians to cater to the interests of a few; others say proportional systems prompt politicians to be relatively more prone to narrow interests. This study suggests that both positions can be correct under different conditions. Politicians competing in plurality systems privilege voters with a shared narrow interest when such voters are geographically concentrated, but when they are geographically diffuse, such voters have greater political influence in proportional electoral systems. Government spending on subsidies in fourteen developed countries provides empirical support for this argument.