Biological Basics and the Economics of the Family

Many economic models of the family are based on a generic "person 1 - person 2" household or "parent - child" family, rather than their anatomically correct counterparts: sons and daughters, fathers and mothers, and grandfathers and grandmothers. These economic models can offer powerful insights into family behavior, but also can leave certain patterns unexplained and neglect potentially important crosscurrents. "Bio-founded" approaches explicitly consider sex differences in reproductive capabilities and constraints, and can illuminate differences in the goals and interests of men versus women regarding preferences for a mate, decisions to marry or to terminate a marriage, how much to invest in a relationship, how much to invest in children, and how much to value the quality relative to the quantity of children Melding biological insights with family economics can cast new light on existing knowledge and open up novel paths for research. This paper generates biologically based hypotheses about family behavior by using Hamilton's rule, which holds that the costs and benefits of altruistic acts are weighted by the closeness of the genetic relationship, and by noting various fundamentals of human reproductive biology (for instance, a father might be uncertain of his genetic relationship to offspring, but a mother almost never is). This strategy generates a unified approach for modeling diverse aspects of family behavior. My discussion of biological fundamentals will include applications, empirical illustrations, and suggestions for how to merge these basics with current economic thinking.