能源效率动态与气候政策

We study the effectiveness of climate change mitigation policies in reducing carbon emissions, focusing on the channel of economy-wide energy efficiency. Using US data, we estimate an impulse response function (IRF) that characterizes how energy efficiency responds to energy price shocks. Standard climate-economy models cannot replicate the slow transition dynamics observed in the data. We build a tractable model that nests the existing literature and can closely replicate the empirical IRF. The slow dynamics in our model imply that carbon taxes reduce short-run and cumulative emissions less than predicted by standard models. The slow dynamics also imply that higher carbon taxes and greater reductions in output are needed to achieve a given environmental target.