Proportional Representation,Majoritarian Legislatures,and Coalitional Voting

Voters in elections under plurality rule face relatively straightforward incentives. In proportional representation systems, voters face more complex incentives as electoral outcomes don’t translate as directly into policy outcomes as in plurality rule elections. A common approach is to assume electoral outcomes translate into policy as a vote‐weighted average of all party platforms. However, most of the world’s legislatures are majoritarian institutions, and elections in PR systems are generally followed by a process of coalition formation. Results obtained using this assumption are not robust to the introduction of even minimal forms of majoritarianism. Incentives to engage in strategic voting depend on considerations about the coalitions that may form after the election, and the voters’ equilibrium strategies are shaped by policy balancing and the postelectoral coalition bargaining situation, including considerations about who will be appointed the formateur.