Religion has long been theoretically linked to processes of stratification, and an impressive body of recent empirical research demonstrates how religious affiliation, practice, and belief are associated with economic outcomes. Given the power of religion and religiosity to explain differences across individuals in education, occupation, income, and wealth, one might easily conclude that increasing religiosity in a society should be expected to cause existing levels of economic inequality in that society not merely to persist but also to grow. There are also good reasons to think that causal influence may run in the opposite direction, however, from economic inequality to religiosity.

The relative power theory contends that religion serves not only as a source of comfort to those who are disadvantaged but also as a means of social control for the advantaged. As economic inequality increases, this argument goes, the wealthier members of a society will, first, be more attracted to religion and, second, be better able to spread their religious beliefs to everyone else. The result is that higher levels of religiosity follow from higher levels of inequality (see Solt, Habel, and Grant 2011). I review this theory in brief next.