The dynamics of political polarization and voting on economic issues: evidence from the Polish parliament, 2005–23
研究波兰议会2005-2023年投票数据，发现政治极化加剧，经济议题更难达成共识，投票主要受政府-反对派对立驱动，且跨党派投票极少，表明政党纪律是极化的重要推手。
Abstract There have been growing concerns that political polarization is intensifying. These concerns, however, are primarily based on anecdotal evidence, aggregate measures related to political competition, or survey data that aim at eliciting public opinion. We adopt a different approach and look at polarization among the political elite. We examine the degree of consensus in parliamentary voting in the Polish parliament between 2005 and 2023. We find that political polarization was on the rise and that reaching agreement between the parties was more difficult when the votes concerned economic issues. Our results also demonstrate that voting in Parliament essentially became one-dimensional in that it was mainly driven by the government-opposition divide. We also document that voting against the party line was extremely rare, whether the MPs were in the government or an opposition party. This suggests that party discipline may be an important driver of political polarization.