The Changing Politics of Renewable Portfolio Standard Adoption: Comparing Political Support in the 1990s and 2000s

This paper is a replication of “Why Do States Adopt Renewable Portfolio Standards?: An Empirical Investigation” by Lyon & Yin. We correct coding errors in the original paper and demonstrate that one reason that Lyon and Yin’s updated model has so little predictive ability is that the political and economic factors that influence RPS passage have changed over time. Using an updated version of Lyon and Yin’s dataset that extends the observations to 2009 and corrects the coding errors, we show that during the 1990s, when the Republican Party was less opposed to environmental legislation, economic factors including u nemployment and energy prices accurately predicted RPS passage. This dynamic shifted in the 2000s, as environmental issues became more politicized and Republicans withdrew their support for renewable energy promotion. For this second period, the party affiliation of the governor and the party breakdown in the state legislature predicts passage of mandatory state renewable energy standards.