A drawback of electoral competition

In most major democracies there are very few parties compared tothe numberof possible policy positions held by voters. We provide an efficiency rationale for why it might be appropriate to limit the proliferation of parties. In our model, the larger the number of parties, the greater the inefficiency of the outcome of electoral competition. The reason is that, when the number of parties increases, electoral incentives push each party to focus its electoral promises on a narrower constituency, and then special interest policies replace more efficient policies that have diffuse benefits. The analysis provides a possible explanation for the existence of institutional features that limit the extent of electoral competition: thresholds of exclusion, runoff electoral systems, and majoritarian two-party political systems.