This provides a dataset of the adoption of 17 different climate and energy policies by each of the 50 states in the U.S. for the period 1990-2014 based on state-specific information from C2ES (2017) and Morey and Kirsch (2016). Each of the policy variables are set to zero before adoption and one after adoption. This new dataset also incorporates a time-series data on electricity price [USD], population, and CO2 emitted in the electricity sector [metric ton, MT] for each state. During data processing, we also created two variables, named export ratio and emissions intensity. Export ratio is the percentage of a state's total electricity production that is exported to other states. It is set to zero if it a state is a net importer of electricity. We derived the state-level emissions intensity from EIA's "Net Generation by State by Type of Producer by Energy Source" (EIA 2016) and EPA's "State CO2 Emissions from Fossil Fuel Combustion, 1990-2014" (EPA 2016) reports. To determine a state's emissions intensity, we divided state-level electric power sector CO2 emissions [in million metric tons, MMT] by state-level electric power industry generation [MWh] for each year from 1990-2014. By 2014, Connecticut, New York, and Oregon have adopted 10 or more policies and some, including climate action plan and binding Renewable Portfolio Standards have been adopted by more than 30 states. This new dataset can be used to assess the effectiveness of different policies on reducing emissions from the electricity sector and bring insights into policy adoption to mitigate climate change within the United States.

Supplement to: Martin, Geoff; Saikawa, Eri (2017): Effectiveness of state climate and energy policies in reducing power sector CO2 emissions. Nature Climate Change, 7, 912-919