A renewable portfolio standard (RPS) policy is a popular regulatory tool implemented within the U.S. and abroad to limit energy sector emissions and incentivize renewable energy. Assessing their effectiveness and efficiency is a key component of achieving further reductions. We assess an energy market under an RPS using fixed-effects panel and 2SLS regression models to lend empirical credence to common theory-based concerns about RPS policy, namely (1) that they leave emissions unregulated once the RPS requirement is met and (2) that they do not incentivize full use of renewable energy resources. Our results show these to be valid concerns that should be considered in the selection, design, and implementation of current or future RPS policies
