Gender-role identity in adolescence and women fertility in adulthood
利用学校年级队列中同伴兄弟姐妹数量的准随机变异，研究发现青少年时期接触多兄弟姐妹同伴会降低女性成为母亲的可能性，但会增加已有子女女性的生育数量，且同伴效应受母亲关系、学校联结等青少年环境影响。
This paper investigates how adolescent exposure to peers from larger or smaller families influences women’s fertility decisions later in life. We distinguish between the extensive margin (whether to become a mother) and the intensive margin (how many children to have), using quasi-random variation in peers’ number of siblings across school-grade cohorts as an identification strategy. Our findings reveal that while exposure to peers with more siblings increases fertility at the intensive margin, it decreases the likelihood of becoming a mother at the extensive margin. We interpret this asymmetry through the lens of theory of economic identity: conforming to social norms entails costs, which are higher when deciding to enter motherhood than when choosing to expand an existing family. Further analysis reveals that adolescent social environments condition peer influence at the intensive margin. Specifically, maternal relationships, school connectedness, parental engagement, and exposure to working mothers shape how young women perceive the costs of conforming to fertility norms. Women with weaker parental and school ties are more susceptible to peer effects, while those exposed to working mothers among their peers perceive lower opportunity costs and are more likely to conform to high-fertility norms. These results underscore the differentiated nature of peer influence across fertility decisions and the critical role of adolescent contexts in shaping long-term demographic behavior.