The Ethnic Power Relations (EPR) dataset identifies all politically relevant ethnic groups, their size, and their access to state power in every country of the world with a population of at least 250,000 from 1946 to 2017. It includes annual data on over 800 groups and codes the degree to which their representatives hold executive-level state power, from total control of the government, power-sharing to overt political discrimination. Also, it provides information on regional autonomy arrangements.