Who Backs the Costs? Voter Coalitions and Party Support for Costly Climate Policies

Political parties are key actors in translating public support for climate action into concrete policy output. While previous research has identified when parties prioritize the issue, less is known about the types of climate policies they endorse and the conditions shaping these choices. This paper examines when parties support climate protection measures that are costly to citizens —such as carbon taxes, fuel taxes, or bans on combustion engines—that are central to effective mitigation. It is argued that support for such measures de-pends on the composition of parties’ voter coalitions, rooted in modern socio-economic cleavages. Extend-ing the model of constrained partisanship, it is shown how socio-cultural and business-finance professionals drive backing for costly policies. Parties drawing primarily on these groups are expected to show the strongest support for costly policies. This expectation is further refined to account for coalitions in which these groups do not constitute a majority. Beyond identifying when and which policies parties support, the framework accounts for variation in climate positions within party families across countries. The framework further explains cross-national variation in climate ambition as a function of differing socio-economic structures. To test these arguments, a novel dataset identifying and classifying climate-related policy proposals in party manifestos is employed, covering 33 countries between 1990 and 2020. The dataset is a significant contribution to existing research as information on which specific climate protection policies parties support is lacking. Combined with survey data, the analysis investigates how voter coalition composition shapes parties’ climate policy platforms.