Hermaphroditism is rare and phylogenically in decline among animal species. The evolutionary basis for this development is not well understood. This paper focusses on self-incompatible simultaneous hermaphroditism in animals. It proposes that such hermaphroditism is not stable in sufficiently...

Why are we not hermaphrodites? This paper argues that while hermaphroditism is an efficient means by which genes may propagate themselves, inherent tendencies towards polygyny undermine its stability. Understanding the forces that have established a segregation of sex functions between male and...

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...

Edlund and Korn [2002] (EK) proposed that prostitutes are well paid and that the wage premium reflects foregone marriage market opportunities. However, studies of street prostitution in the U.S. have revealed only modest wages and considerable risks of disease and violence, casting doubt on...

Crime rates almost doubled in China between 1992 and 2004. Over the same period, sex ratios (males to females) in the crime-prone ages of 16-25 years rose sharply, from 1.053 to 1.093. Although scarcity of females is commonly believed to be a source of male antisocial behavior, a causal link has...

Young women go to prosperous areas, leaving economically backward places with a deficit of fertile women. This phenomenon is common throughout the developed world. The proposed reason is that women have two sources of income: men and work, and both the good men and the good jobs tend to be in...

Using estate tax returns data, we observe that the share of women among the very wealthy in the United States peaked in the late 1960s at nearly one-half and then declined to one-third. We argue that this pattern reflects changes in the importance of dynastic wealth, with the share of women...

Male and female social roles are largely predicated on the fact that male and female reproductive functions are separated in different individuals. This paper asks why gonochorism rather than hermaphroditism, is the rule among vertebrates. We argue that hermaphroditism may be unstable in the...