The Evolution of the Immigration Debate: Evidence from a New Dataset of Party Positions Over the Last Half-Century

Immigration is one of the most contentious issues across contemporary democracies, but this has not always been the case. What accounts for this development? We study how immigration has evolved in the political debate in Western Europe over five decades by creating and analyzing a comprehensive new data set—Immigration in Party Manifestos (IPM)—of all immigration-related appeals made in preelection manifestos by major parties. Our account focuses on three central debates. First, contra to perceived wisdom, we find no evidence of polarization between left and right. Instead, we document a striking co-movement. Second, we find only modest support for the argument that the success of anti-immigrant parties significantly shapes how centrist parties position themselves on immigration. Finally, our evidence counters the claim that cultural issues have overtaken the debate over immigration. Although the prominence of immigration-related cultural appeals has increased in certain countries and elections, the economic dimension has remained prevalent.