From Polygyny to Serial Monogamy: a Unified Theory of Marriage Institutions∗ David de la Croix† Fabio Mariani‡ April 10, 2012 Abstract Consider an economy populated by males and females, both rich and poor. The society has to choose one of the following marriage institutions: polygyny, strict monogamy, and serial monogamy (divorce and remarriage). After having identified the conditions under which each of these equilibria exists, we show that a rise in the share of rich males can explain a change of regime from polygyny to monogamy. The introduction of serial monogamy follows from a further rise in either the proportion of rich males, or an increase in the proportion of rich females. Strict monogamy is a prerequisite to serial monogamy, as it promotes the upward social mobility of females more than polygyny. We also show that polygyny is compatible with democracy. JEL Classification Codes: J12; O17; Z13. Keywords: Marriage; Polygyny; Monogamy; Divorce; Human capital; Political economy. ∗The authors acknowledge the financial support of the Belgian French speaking community (ARC conventions 09-14019 on “Geographical mobility of factors”, and 09-14018 on “Sustainability”). We thank Pierre Dehez, Oded Galor, Cecilia Garcia-Pe˜nalosa, Shoshana Grossbard, Nippe Lagerl¨of, Margherita Negri, Daniel Weiserbs and participants at the workshop on Cultural Change and Economic Growth in Munich (2011) and the ASSET 2011 Annual Meeting in Evora, as well as seminar participants in Namur (FUNDP) and Louvain-la-Neuve (IRES) for helpful comments on earlier drafts. †David de la Croix: IRES and CORE, Universit´ecatholique de Louvain, B-1348 Louvain-la-Neuve, Belgium. E-mail:
[email protected] ‡Fabio Mariani: IRES, Universit´ecatholique de Louvain; Paris School of Economics; IZA, Bonn.