Sex and the City (Columbia University)

Sex and the City

Lena Edlund*

Columbia University, New York,

NY 10027, USA


Throughout the industrialized world, young women outnumber young men in urban areas. This paper proposes that such a pattern may be linked to higher male incomes in urban areas.

The argument is that urban areas offer skilled workers better labor markets. Assuming that there are more skilled males than females, this alone would predict a surplus of males. However, the presence of males with high incomes may attract not only skilled females but also unskilled females.

Thus, a surplus of women in urban areas may result from a combination of better labor and marriage markets. Swedish municipality data support the results. Keywords: Sex ratio; marriage migration JEL classification: J6; J16; R23 I.

Introduction Throughout the Western world, rural areas are short of young women (see Table 1).

Urban areas are not only home to relatively more females, they also offer better labor markets for skilled workers.

However, since women are on average less skilled than men, job location alone cannot account for the surplus of women. This paper argues that a combination of marriage and labor market factors may explain the observed pattern. It is well established that, in partner choice, men value traits that are associated with female fecundity, such as youth; for evidence, see e.g. Wright (1994) and Buss (1994).

 Female fecundity is not only attractive but also scarce; see Trivers (1972). Hence young women tend to have a choice of partners.

If women value financial security when evaluating a partner, richer men would face better partner availability; again, see Wright (1994) and Buss (1994). These observations suggest that young women would match with rich men. If such men are in urban areas, this could account for the surplus of women

By symmetry, it might be argued that if young women congregate in urban areas, men would also be attracted by better marriage market opportunities in urban areas, which should balance the sex ratio.

However, this is not necessarily true. If the marriage market is asymmetric—so that for men, marriage follows from good job-market opportunities, but for women, marriage and wage work constitute two alternative sources of income—high paying jobs in a locality may imply that it can support more women than men, since women draw income from both jobs and men. This paper is in the vein of a small economics literature on family and location choice. Mincer (1978) and Costa and Kahn (2000) analyzed couples’ location choice where matching was taken as given.

These papers assume that couples co-reside, and thus cannot account for variation in the sex ratio.

Another related paper is Konrad, Ku¨nemund, Lommerud and Robledo (2002), which studied the location choice of siblings, given birth order. While the surplus of young women in cities has been noted in the popular press, this is the first economics paper that, to the best of my knowledge, analyzes the phenomenon systematically. The remainder of the paper is organized as follows.

Section II considers whether it is reasonable to assume that, in the Western world, men pay women (as partners in general and wives in particular).

Section III provides a rudimentary model and Section IV reports evidence from Swedish municipality data. Section V concludes. II.

Why Men Pay Women While it takes a man and a woman to produce a child, and sex ratios roughly balance, Trivers (1972) argued that women’s greater parental investment makes them bottlenecks in reproduction.

The female parental investment is greater than that of the male (in the vast majority of species), starting with the (by definition) greater energy invested in the female sex cell and, among humans, further amplified by a nine-month gestation period.

Moreover, women are fecund for fewer years than males. Although a woman cannot reproduce in splendid isolation, beyond the first male, the contribution of additional partners to the number of offspring a woman can bear is negligible. In contrast, a man’s ability to father children is strongly linked to his ability to attract partners, an observation first made by Bateman (1948).

Hence, the reproductive rewards to additional partners are much greater for males than females. As a consequence, male-to-male competition for partners tends to be greater than female-to-female

In his study of the fruit fly, Bateman found that female reproductive success was unrelated to an ability to attract partners, while male reproductive success was an almost linear function of the same ability. # The editors of the Scandinavian Journal of Economics 2005. Sex and the city 27 partner competition. This in turn provides the conditions for a partner market in which males contribute resources in exchange for mating opportunities.

Humans not only mate, they also marry. As argued by Edlund (2001), marriage may induce even greater male-to-female transfers. The underlying rationale may be summarized by the Roman dictum Mater semper certa est, pater est, quem nuptiae demonstrant.

In other words, in the absence of marriage, there is only one known parent—the mother. She is the default custodian of her children and, unless married, she is also the sole custodian.

If the mother is married, fatherhood accrues to her husband. Moreover, a married mother shares custody with her husband.3 Since marriage establishes paternity and gives men custodial rights (some of which are at the expense of the mother’s rights), men could be expected to pay for marriage. In fact, marriage may be viewed as a contract through which men transfer resources to women in exchange for parental rights.

This observation was used by Edlund and Korn (2002) to explain why prostitutes are well paid (they cannot marry), and by Edlund and Pande (2002) to understand why the decline in marriage over the last three decades may have made women poorer relative to men and thus more left-leaning politically.4 While men may pay for mating opportunities and marriage, this does not necessarily imply that they pay women. In societies which practice bride price, the payment is not to the bride but to her father; see Goody (1973).

Typically, bride price payments reflect that the right to decide marriage is vested in a bride’s male relative, not the bride. However, in Europe since the Middle Ages, and in many other countries with Western-inspired family law since the 1950s, only the intending spouses need to consent for the marriage to be valid; see Goody (1983) and Goode (1970).

 If women decide whom to partner with or marry, it stands to reason that they would be the beneficiaries of male-to-male competition for partners.

In Europe, large up-front payments have been rare.

Instead, the payment seems to have taken the form of higher transfers during marriage and there is ample evidence that, historically, women in Europe have enjoyed higher status than women in Asia. For instance, men and women have shared quarters and often taken meals together, which can be contrasted with the Asian practice of purdah.

Moreover, on the death of her husband, the widow inherited, a practice that contrasts with custom in Africa and Asia, where she did not inherit and may even have been considered part of the estate.8 Arguably, many societies mandate monogamy, thereby adding institutional constraints on a man’s ability to father children (in-wedlock). While monogamy reduces the gender differences in reproductive capacity, it does not eliminate them. First, not all partnering is between people who are married to each other. Second, monogamy is rarely strict.

Remarriage is typically allowed on divorce or death of a spouse.9 A widower or divorce´ can remarry and have children if his new wife is young, while the widow or divorce´e beyond a certain age cannot bear children irrespective of her partner’s age. If ability to reproduce contributes to attractiveness, gender differential fecundity will make women scarce on the partner market—even under monogamy—as long as there is some repartnering.

This asymmetry was exploited by Siow (1998) in his analysis of the implications of differential fecundity for labor market behavior. Lastly, monogamy may raise the rewards associated with marriage to a high-income husband since he can only take one wife. Thus, while the number of men and women who are married at any given point in time will balance under monogamy, this does not mean that the sex ratio in a locality has to approach unity, since unmarried women may be attracted by the potential to marry well (and be the sole wife).