I present in this paper the skeleton of a theory of marriage. The two basic assumptions are that each person tries to do as well as possible and that the “marriage market” is in equilibrium. With the aid of several additional simplifying assumptions, I derive a number of significant implications about behavior in this market. For example, the gain to a man and woman from marrying compared to remaining single is shown to depend positively on their incomes, human capital, and relative difference in wage rates. The theory also implies that men differing in physical capital, education or intelligence (aside from their effects on wage rates), height, race, or many other traits will tend to marry women with like values of these traits, whereas the correlation between mates for wage rates or for traits of men and women that are close substitutes in household production will tend to be negative. The theory does not take the division of output between mates as given, but rather derives it from the nature of the marriage market equilibrium. The division is determined here, as in other markets, by marginal productivities, and these are affected by the human and physical capital of different persons, sex ratios (that is, the relative numbers of men and women), and some other variables.
Becker, G. S. (1973). A theory of marriage: Part I. Journal of Political economy, 81(4), 813-846.