Fertile soil: explaining variation in the success of Green parties

Comparative political science has largely ignored the marked cross-national variation in Green party electoral performance. This article uses a unique aggregate dataset of 347 parliamentary elections from 32 countries over the course of 45 years to test competing theories about the causes of Green party success. The findings show that voter demand, institutions and mainstream party strategy all affect the Green vote. Green parties do well in societies with post-materialist conflicts caused by high levels of wealth or the presence of a tangible environmental dispute. The article also shows that regional decentralisation helps Green parties, but electoral systems have little effect on their vote share. Most importantly, it demonstrates that the impact of mainstream party strategy on Green electoral strength is dependent on the age of the Green party. While mainstream parties can undermine young Green parties by adopting the environmental issue, this effect is reversed once the Greens have survived a number of elections. Thus 'accommodative' mainstream party strategies eventually boost the Green vote by increasing the salience of the key Green issue.