There is a long and venerable tradition of examining religion within the context of political economy. Karl Marx famously declared that religion is the opiate of the masses, and explained religion as an epiphenomenon arising from an economic foundation. Max Weber reversed the causal arrow in his landmark work, The Protestant Ethic and the Spirit of Capitalism, and argued that religious beliefs powerfully influenced economic history. More recently, economists have used rational choice and game theory to explain various aspects of religiosity. There is little doubt that economy and religion have long been locked together in a cultural embrace that deserves serious and critical scrutiny. This Category will examine the linkages between religion and economy.