We review a class of adverse environmental externalities that accompany consumption and procreation. We also identify externalities that are traceable to socially embedded preferences for family size. Those preference structures can give rise to a heightened demand for children, exacerbating the environmental externalities households impose on future generations. Our analysis exposes weaknesses in basing family planning programs entirely on individuals' reproductive rights. We offer a rough idea of the magnitude of global environmental externalities by estimating the size of world population the biosphere can support at the standard of living enjoyed in high middle-income countries. Today's population and future global population projections far exceed our estimate, suggesting that unless significant resource-saving technological progress and life-style changes take place, the UN's Sustainable Development Goals are unsustainable. We conclude that family planning has been undervalued by national governments and international agencies.
Published in a peer-reviewed journal of the Population Council. Aisha Dasgupta is Associate Population Affairs Officer, United Nations Population Division, New York. Partha Dasgupta is Frank Ramsey Professor Emeritus of Economics, University of Cambridge; Fellow of St John’s College, Cambridge; and Visiting Professor, New College of the Humanities, London.