Parties, Legislators, and the Origins of Proportional Representation

Conventional wisdom is that the adoption of proportional representation (PR) in many European democracies in the early 1900s came about as a strategic effort by traditional conservative parties to preserve political power after the extension of the franchise and industrialization increased the vote base of leftist parties. This explanation treats political parties as unitary actors, ignoring the potential variation in incentives faced by individual legislators. We consider how the incentives to vote for PR were determined by party leaders’ concerns over government formation as well as by individual legislators’ district-level electoral concerns. Using roll-call data from six different reform proposals in Norway in 1919, we document considerable within-party variation in the political support for electoral reform: frontbenchers and future cabinet ministers were more likely to vote in favor of adopting PR than backbenchers, and legislators occupying safe seats in the pre-reform period were less likely to vote in favor.