Social Democratic Party Exceptionalism and Transnational Policy Linkages

Political parties learn from foreign incumbents, i.e., parties abroad that won office. But does the scope of this cross-national policy diffusion vary with the party family that generates incumbents? We argue that party family conditions transnational policy learning when it makes information on the positions of sister parties more readily available and relevant. Both conditions apply to Social Democratic parties. Unlike other party families, Social Democrats faced major competitive challenges from the 1970s and they exhibit exceptionally strong transnational organizations – factors that, as we contend, uniquely facilitate cross-national policy learning from successful parties within the family. We analyze parties’ policy positions using spatial methods and find that Social Democratic parties are indeed exceptional as they emulate one another across borders more than Christian Democrats and Conservatives. These findings have important implications for our understanding of political representation and of Social Democratic parties’ election strategies over the last forty years.