Impact of Sibship Size, Birth Order and Sex Composition on School Enrolment in Urban Turkey*
利用土耳其城市数据，通过工具变量法分析兄弟姐妹数量、出生顺序和性别构成对儿童入学率的影响，发现出生顺序呈抛物线效应（中间孩子更差），性别构成仅影响女孩，且这些效应在贫困家庭更显著。
Abstract This paper investigates, in a unified framework, the effects of sibship size, birth order and sibling sex composition on children's school enrolment in urban Turkey. We utilize an instrumental variable estimation method to address parents’ joint fertility and schooling decisions using twin births as instruments. We find no causal impact of sibship size on school enrolment. However, there is evidence for a parabolic impact of birth order where middle‐born children fare worse. Sex composition of siblings matters only for female children. Our finding that birth order and sibling sex composition matter more for poorer households suggests that scarce financial resources play an important role in bringing about the sibling composition effects.