We examine sources of variation in possession and use of the death penalty using data drawn from 193 nations in order to test theories of punishment. We find the death penalty to be rooted in a country's legal and political systems, and to be influenced by its religious traditions. A country's level of economic development, its educational attainment, and its religious composition shape its political institutions and practices, indirectly affecting its use of the death penalty. The article concludes by discussing likely future trends.