Transplants of donated stem cells save the lives of many patients with blood diseases. Donation is somewhat painful, but rarely has lasting adverse effects. Patients can accept transplants only from donors with compatible immune systems. Those lacking a sibling match must seek donations from the...

Large, short-run fluctuations in the birth rate have been an important demographic feature of industrialized, low-fertility populations in the twentieth century. Since females normally marry men who are two or three years older than themselves, these fluctuations result in large imbalances...

This paper considers a series of examples in which evolution supports cooperative behavior in single-shot prisoners' dilemma. Examples include genetic inheritance for asexual siblings and for sexual diploid siblings. We also study two models of ``cultural inheritance''; one in which siblings...

This paper is an advertisement for some facts and ideas that I think likely to lead to a richer theory of the economics of the family. The discussion references many papers from anthropology and biology. Because of the intimate connection between the family and reproduction, it should not be...

This paper explores the evolutionary foundations of altruism among siblings. It is intended as a contribution to the theory of the evolution of preferences, the economics of the family, and the evolutionary biology of kin selection. This paper extends the kin- selection theory of the biologist,...

Consider a public utility that offers its service at two different times. We study the effects of a change from uniform pricing throughout the day to peak-load pricing. We show that for a utility constrained to operate with a fixed rate of return on capital, the introduction of peak-load pricing...

In most times and places, women on average marry men who are older than themselves. We propose a partial explanation for this difference and for why it is diminishing. In a society where the economic roles of males are more varied and specialized than the roles of females, it may be that the...

About 80\% of all societies recorded by anthropologists are polygynous (men have many wives). Even our own society is less monogamous than claimed. This paper attempts to explain such mysteries as why bride prices and dowries are not ``opposites'', why polygamous societies are usually...

This paper explores the workings of stratified societies in which there is primogeniture and where the nobility practice monogamous marriage with a double standard of sexual fidelity. We model a simple stratified society and define the reproductive values of the male and female nobility relative...