This paper investigates whether the sources of income, not just the levels, determine whether an individual is monogamous. Our results support the idea that polygyny stunts development by allowing wealthy men to acquire wives rather than investing in child quality.

This Paper examines why developed countries are monogamous while rich men throughout history have tended to practice polygyny (multiple wives). Wealth inequality naturally produces multiple wives for rich men in a standard model of the marriage market where polygyny is not ruled out. Our model...