Out of the green : policy diffusion in the European Green Party

Abstract

Recent work in the policy diffusion literature shows that left-right policy positions and issue emphasis are influenced by successful political parties abroad. Despite these findings, important questions remain about where and under what conditions policy diffusion between niche parties occurs. My research sheds light on these puzzles by showing that transnational party organizations (henceforth Europarties) are institutionalized mechanisms for policy diffusion between niche parties in the EU. In addition, I examine the conditionality of this relationship based on electoral rules and the substantive effects that policy diffusion has on vote share. To answer these puzzles, I use data from the Manifesto Research on Political Representation (MARPOR), Comparative Political Dataset (CPDS), and original data on Europarty membership. From these data, I construct, primarily, a sample of green parties and test my theory using spatial econometrics models. I find that niche parties do indeed learn through Europarties, which act as institutionalized arenas of policy diffusion. Further, learning is conditional based on the similarity of the electoral systems of the parties. Lastly, though learning does occur, green parties do not reap any electoral benefits from learning from their neighbors. These findings indicate that Europarties play an important role in the national politics of European countries by acting as a venue for like-minded party elites to learn from each other.