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Does fertility behavior spread among friends?

Number: 50
Year: 2012
Author(s): Nicoletta Balbo, Nicola Barban
Keywords: transition to parenthood,add-health,social interaction,peer effect
This paper investigates how social interactions among friends shape fertility. We specifically examine whether and how friends' fertility behaviour affects an individual's transition to parenthood. By integrating insights from economic and sociological theories, we elaborate on the mechanisms via which interactions among friends might affect an individual's risk of becoming a parent. By exploiting the survey design of the Add Health data, we follow a strategy that allows us to properly identify interaction effects and distinguish them from selection and contextual effects. We engage in a series of discrete time event history models with random effect at the dyadic level. Results show that, net of confounding effects, a friend's childbearing increases an individual's risk of becoming a parent. We find a short-term, curvilinear effect: an individual's risk of childbearing starts increasing after a friend's childbearing, it reaches its peak around two years later, and then decreases.

Nicoletta Balbo

Universita Bocconi, Dondena Centre for Research on Social Dynamics


Nicola Barban

Groningen University, Department of Sociology


Keywords: transition to parenthood; add-health; social interaction; peer effect


Download: The paper may be downloaded here.