High rates of polygyny do not lock large proportions of men out of the marriage market

There is a widespread belief, in scholarly literature, the popular press, and even incel ideology, that polygyny prevents many men from marrying, by skewing the sex ratios of marriage markets. In turn, high proportions of men permanently excluded from marriage are thought to lead to negative outcomes, such as increased rates of crime and conflict. We investigate the link between polygyny and unmarried men through a combination of formal demographic modeling and analysis of census data from 30 countries in Africa, Asia, and Oceania, plus the historical United States. Our model demonstrates that marriage markets are skewed sufficiently feminine under a range of realistic demographic scenarios to support some level of polygyny without necessarily locking any men out of marriage. In fact, our empirical results show a negative association between the prevalence of polygyny and the prevalence of unmarried men at the sub-national level. This pattern is explained partly by differences in sex ratios across populations and partly by relatively strong pro-marriage norms increasing the overall rate of marriage in polygynous communities. These results challenge the “if one man marries two women, another man will go unmarried” mechanism that is commonly invoked to link polygyny to armed conflict, to argue for the evolutionary fitness of monogamy, and to bolster certain strains of incel ideology.