Do trusting regions vote for Green parties? A post-materialist values channel in 21st-century Europe

While previous studies link social capital to environmental attitudes, we take a step further and ask whether trust translates into actual behaviour — voting for a Green party. We propose a post-materialist values channel through which social capital relates to Green electoral support, and examine it across European regions in one of the first studies of trust and observed electoral behaviour. Unlike most work, which relates survey-based attitudes to survey-based vote intentions, our dependent variable is real behaviour: the regional vote share of 41 European Green parties in parliamentary elections (2002–2022), matched with regional trust indicators from the European Social Survey. The estimations confirm our hypothesis that higher trust relates positively to Green electoral results, with highly statistically significant and robust associations for social, institutional, and international trust. A one-standard-deviation rise in regional social trust is associated with a 0.1-standard-deviation rise in Green support. In addition, post-materialist attitudes appear more important than redistributive preferences, and these associations are stronger in high-trust regions. This suggests that, in 21st-century Europe, typical Green voters are less oriented towards the left than previously thought and more driven by post-materialist values.