Peers and Possible Partners: Exploring the Origins of Population Long-term Equilibria
I was awarded an ERC Starting grant 2021 to study how social interactions, through peer effects and matching markets, shape population dynamics.
Abstract: Population dynamics are a crucial driver of the prosperity of nations. Nowadays, fertility is too high in less developed countries, impeding their escape from poverty, and too low in more developed countries, threatening their very existence. Another concern is the global rise of childlessness among men, which correlates with mental health issues and social unrest. P3OPLE contributes to addressing these challenges by studying how social and market interactions shape the dynamics and distribution of fertility. I will introduce and test the empirical relevance of two novel concepts: high/low fertility traps and involuntary male childlessness. The first concept revolves around peer effects in fertility preferences and revisits an unsettled debate: why are some communities trapped in sub-optimally high or low fertility equilibria? I will discuss how information and coordination failures, conformism and competition, as well as immigration, can prevent or facilitate fertility change. The second concept deals with general equilibrium effects on the matching market and raises an unexplored question: can a man be involuntarily childless due to a relative scarcity of female partners on the matching market? I will quantify the importance of unbalanced sex ratios, polygamy and serial monogamy as drivers of reproductive inequalities. Both concepts cross the boundaries of disciplines by integrating insights from demography, sociology and evolutionary biology into economic frameworks. The methodology will combine economic theory and cutting- edge empirical analysis, including experimental, observational and structural methods, to provide quantitative evidence on novel causal links. Finally, I will build databases with information on male fertility and subjective determinants of fertility never consolidated or collected at such a large scale. They will allow researchers to answer open questions and explore novel ideas inspired by hitherto undocumented patterns.
Related publications
Rossi and Xiao (2024), "Spillovers in Childbearing Decisions and Fertility Transitions: Evidence from China", Journal of the European Economic Association, Vol. 22(1), pp.161-199.
Dupas, Jayachandran, Lleras-Muney and Rossi (2025), "The Negligible Effect of Free Contraception on Fertility: Experimental Evidence from Burkina Faso", American Economic Review, Vol. 115(8), pp.2659-88.
Rossi and Xiao (2026), "Left over or Opting out? Squeeze, Mismatch and Surplus in Chinese Marriage Markets", Journal of Development Economics, Vol. 179, 103629.
Gobbi, Hannusch and Rossi (2026), "Family Institutions and the Global Fertility Transition", Journal of Economic Perspectives, Vol. 40(1), pp.47-70.
Rossi and Valente (2027), "Contraceptive Access, Fertility and Well-being in Lower Income Countries", Oxford Handbook on the Economics of Fertility and Reproductive Health, Chapter 20, forthcoming.
Rossi (2027), "Childlessness and the Marriage Market", Population, 80th anniversary issue, forthcoming.
Related working papers
Dupas, Falezan, Mabeu and Rossi, "Long-run Impacts of Forced Labor Migration on Fertility Behaviors: Evidence from Colonial West Africa"
Related work-in-progress (draft available upon request)
Meier and Rossi, "Polygamy as a Ponzi Scheme: How Population Growth Shapes Marriage Markets in Africa"
Rossi and Vallette, "The Serial Monogamist and the Involuntary Celibate: How Divorce Shapes the Gender Gap in Childlessness"
Pasquier, Rossi and Wang, "Estimating Heterogeneous Peer Effects with Partial Population Experiments"