Travail de recherche/Working paper
Résumé : Rising childlessness is now a central margin of very low fertility inmiddle- and high-income countries, where delayed entry into parenthood increasingly risks becoming permanent non-parenthood. Because completedcohort childlessness can only be observed at the end of reproductive life, thischapter develops a period measure of childlessness, analogous to the TotalFertility Rate, that summarizes the age-specific first-birth conditions prevailing in a given year. Applied to the countries for which the measure canbe computed, period childlessness has risen everywhere, reaching aroundone quarter in several Western countries, more than one third in Finland,Japan, and Spain, and 45% in South Korea. To interpret these patterns,the chapter proposes a conceptual framework that moves beyond the conventional distinction between voluntary and involuntary childlessness, distinguishing instead between biological, poverty-driven, opportunity-driven,marriage-market, and mortality-driven routes to non-parenthood. The risein childlessness is then interpreted through a model in which partnershipformation and fertility are jointly determined. We map leading explanationsfor rising childlessness into this unified framework, showing how decliningpartnership surplus, housing costs, gendered child-rearing norms, weakerpro-natalist preferences, and uncertainty affect childlessness through modelprimitives