The science of demography focuses on the drivers of population dynamics: fertility, mortality, and migration. Demography is inherently interdisciplinary and draws on theory from a range of social sciences, including sociology, economics, and anthropology. The demographers’ approach to fertility research at a given time is grounded in the contemporaneous fertility trends and fertility-related technology at the societal and individual levels. For example, the founding of demography at the turn of the twentieth century coincided with declining fertility levels among the most affluent and educated families, a bimodal pattern of high fertility or childlessness among families at the lower end of the socioeconomic spectrum, and Margaret Sanger’s public health efforts to support the availability of contraception. Thus, demography was originally deeply concerned with fertility control as defined by the ability to stop having children after reaching the desired family size. As US fertility patterns settled into nearly universal parenthood with most families having two to four children in the 1950s, demographers turned their attention to “uncontrolled” fertility in the developing countries of Asia and Africa. The most consuming fertility issues of the 1970s reflected the technological development of the contraceptive pill and the social development of increasingly non-legitimated teen births.
In the twenty-first century, much about fertility has changed. Some lines of differentiation in fertility patterns among Americans have lost their influence, as seen in the general convergence in completed family size across religious backgrounds. Many more methods of contraception are available and access to knowledge of these technologies has generated fertility declines for families across the world except for parts of Africa. But fertility-related technologies for creating and maintaining pregnancies have only become highly developed in recent decades, and their use has not yet become widespread enough to make an impact at the societal level (for a first analysis, see the work of Hoorens and colleagues ). Demographers today spend less scientific effort on fertility control as traditionally explored, but they have not yet felt a strong impetus to research aspects of fertility control such as the power to create children around barriers. The science of contraception is well documented and the science of infertility is scant.
Nevertheless, the sociological, economical, and anthropological concepts on which demographers have drawn to explain fertility patterns and contraceptive behavior can be usefully applied to infertility. Here, I begin to lay out how demographic theory and concepts from economics can shed light on questions of interest to researchers in the emerging field of oncofertility, the preservation of biological fertility in cancer patients.