A Strictly Economic Explanation of Gender Roles: The Lasting Legacy of the Plough.

We show that the descendants of ancient farmers may have an interest in marrying among themselves, and thus maintaining the gendered division of labour, originally justified on comparative-advantage grounds by the advent of the plough, even after they emigrate to a modern industrial economy where individual productivity depends on education rather than physical characteristics. The result rests on the argument that, if efficiency requires the more productive spouse to specialize in raising income, and the less productive one in raising children, irrespective of gender, an efficient domestic equilibrium will be implemented by a costlessly enforceable pre-marital contract stipulating that the husband should do the former and the wife the latter. A con-tract may not be needed, however, if time spent with children gives direct utility, because an effi cient equilibrium may then be characterized by little or no division of labour.