Kinship and fertility: Brother and sibling effects on births in a patrilineal system

We estimate the effect of the number and genders of the siblings of parents on their fertility decisions in a patrilineal system. For that purpose we develop a three-step approach that uses the genders of the first and second siblings to identify gender specific sibling effects while taking account of the influence of gender biased preferences and social norms. Using data from China, we find gender asymmetric sibling effects on fertility. Specifically, the number of brothers (but not siblings) of the husband has a negative effect on fertility: an additional brother is associated with 0.1 fewer own children. The evidence is consistent with a model in which the size of a kinship group reduces the strength of the motive to continue one's family lineage and hence reduces the fertility of each member household.