Dear all, A few have mentioned the cause of PR in Western Europe. I think the discovery of a Jonathan Rodden paper prompted this. The short story uncovered in earlier posts is that PR was adopted to prevent Socialist majorities. Stein Rokkan originally gave this hypothesis, and Boix (1999) identified some scope conditions. Here are two more recent papers. Leeman and Mares find support for the Boix-Rokkan argument in Germany. Germany is important because another popular argument says it defies the Boix-Rokkan model, which is said to be a generalization of Belgian history. Here's the Leeman and Mares paper: http://www.princeton.edu/csdp/online-community/historical-theoretical-pe/The-Adoption-of-Proportional-Representation.pdf I like this paper by Calvo (2009). It persuasively addresses a few gaps in the Boix-Rokkan argument, one of which is why Socialists also favored PR. That shouldn't happen if Boix-Rokkan is right. Calvo basically says that new-party entry created old-party seat-vote disproportionalities. He is agnostic on whether new-party entry comes from the enfranchisement of new voters, a split in an existing party, or both. See: http://gvptsites.umd.edu/calvo/Calvo-%2061,%202,World%20Politics,%20April%202009.pdf I have my own argument about party splits and PR in US cities. I don't get into seat-vote disproportionalities because the data are poor, but my argument is closest to Calvo's. See: http://journals.sagepub.com/doi/pdf/10.1177/1532673X16674774. The paywall is down for the moment. I don't know why or how long that will last. Regards, Jack Jack Santucci Ph.D. Candidate in Government Georgetown University http://www.jacksantucci.com 202-681-5225 (Google Voice)