Economics and the life sciences have long shared an interest in population, but in the early 1970s the status of that object changed. Whereas Malthus and his followers treated population growth as an exogenous, iron force pressing in on economics, and whereas neoclassical economists simply bracketed out the problem of human embodiment, economists now used the revamped concept of human capital to reframe population changes as fully endogenous to economic analysis. Reproduction, argued men like Gary Becker, T. Paul Schultz, and H. Gregg Lewis, was a form of capital investment based on the rational expectations of sovereign consumers: having children was like buying a fridge.
My paper explores this microeconomic approach to human life by detailing the rise of modern theories of ‘human capital’ in the late 1950s and their application, in the 1960s, to sex and other areas previously beyond the scope of economic analysis. I show how these ideas developed alongside a new breed of economic model. Bachue-1—a mainframe simulation improbably named after the Columbian “goddess of love, fertility and harmony between nature and man”—was a joint project of the International Labor Organization and the UN Fund for Population Activities, begun in 1972. Unlike previous simulations, which modeled the world “in terms of aggregates such as ‘population,’ ‘national income accounts,’ and so forth,” Bachue was proudly “disaggregated.” Fertility and productivity interacted endogenously, via feedback loops. Through Bachue; Becker; and his colleagues, human reproduction was transformed from a natural bombshell to an individual, rational choice.
