Majority protection: The origins of distorted proportional representation

Not all proportional representation (PR) systems are equally proportional. Some PR systems favour large parties and are thus ’distorted’. What explains the origins of distorted PR? Research on the adoption of PR has identified both consensual and conflict-ridden roads to PR. We argue that these two roads to PR do not lead to the same outcome. We expect the adoption of PR by consensus to result in less proportional PR systems compared to cases in which PR is forced upon powerful parties. Empirically, we find no evidence that powerful parties introduced PR to grant minority groups better political representation. Instead, we show that when PR was adopted with the support of the most powerful party, reforms often resulted in distorted PR and small seat losses for the most powerful party.