Working Paper: CEPR ID: DP16603
Authors: Nicola Barban; Elisabetta De Cao; Marco Francesconi
Abstract: Fertility has a strong biological component generally ignored by economists. Using the UK Biobank, we analyze the extent to which genes, proxied by polygenic scores, and the environment, proxied by early exposure to the contraceptive pill diffusion, affect age at first sexual intercourse, age at first birth, completed family size, and childlessness. Both genes and environment exert substantial influences on all outcomes. The anticipation of sexual debut and the postponement of motherhood led by the diffusion of the pill are magnified by gene-environment interactions, while the decline in family size and the rise in childlessness associated with female emancipation are attenuated by gene-environment effects. The nature-nurture interplay becomes stronger in more egalitarian environments that empower women, allowing genes to express themselves more fully. These conclusions are confirmed by heterogenous effects across the distributions of genetic susceptibilities and exposure to environmental risks, sister fixed effects models, mother-daughter comparisons, and counterfactual simulations.
Keywords: fertility; genetics; polygenic score; contraceptive pill; nature versus nurture; social norms
JEL Codes: D10; I14; I15; J01; J13; J16
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| outcome-specific polygenic scores (PGS) (C15) | age at first sexual intercourse (J13) |
| outcome-specific polygenic scores (PGS) (C15) | age at first birth (J13) |
| outcome-specific polygenic scores (PGS) (C15) | total number of children born to a woman (J13) |
| outcome-specific polygenic scores (PGS) (C15) | likelihood of being childless (J13) |
| pill exposure (Y60) | age at first sexual intercourse (J13) |
| pill exposure (Y60) | age at first birth (J13) |
| pill exposure (Y60) | completed family size (J12) |
| pill exposure (Y60) | probability of childlessness (J13) |
| gene-environment interaction (O44) | genetic predispositions on fertility outcomes (J13) |