Uncontrollable mortality creates selective advantages for families with many “cheap” offspring; declining mortality and medical progress facilitate the transition towards growth-promoting “low-fertility-high-quality” phenotypes

Darwin beats Malthus: evolutionary anthropology, human capital and the demographic transition. Katharina Mühlhoff. Cliometrica, Jun 16 2021. https://link.springer.com/article/10.1007/s11698-021-00234-5

Abstract: Declining mortality seems a natural explanation for the demographic transition. However, many economists have discarded improved infant survival as a causal trigger. Moreover, certain currents in Neo-Malthusian economics point to potentially beneficial side-effects of population shocks. Based on historical demography and evolutionary science, I challenge these views. The argument is that uncontrollable (“extrinsic”) mortality creates selective advantages for families with many “cheap” offspring, whereas stable environments favor child “quality”. Combining “life-history-theory” and a unified growth model, I demonstrate that declining mortality and medical progress facilitate the transition towards growth-promoting “low-fertility-high-quality” phenotypes. As it will turn out, this framework produces qualitatively and quantitatively closer predictions of the historical fertility decline than standard models of the Barro–Becker type. Moreover, evolutionary mechanisms provide a parsimonious explanation for diverse demographic transition patterns. Thus, evolved adaptations add a new and culture-free mechanism to older theories. Moreover, regarding sustainable growth, they suggest that natural selection eventually offsets the benefits from population shocks claimed by Malthusian theories.