The Impacts of Family Size on Investment in Child Quality
利用双胞胎作为家庭规模的外生变化，研究子女数量对子女投资和福祉的影响，发现父母会重新分配资源，符合Becker的数量与质量模型。
Abstract Using multiple births as an exogenous shift in family size, I investigate the impact of the number of children on child investment and child well-being. Using data from the 1980 US Census Five-Percent Public Use Micro Sample, 2SLS results demonstrate that parents facing a change in family size reallocate resources in a way consistent with Becker’s Quantity & Quality model. A larger family generated by twins in a later birth reduces the likelihood that older children attend private school, reduces the mother’s labor force participation, and increases the likelihood that parents divorce. The impact of family size on a measure of child outcome, such as grade retention, is less clear. The results indicate that for both measures of child investment and child well-being, the 2SLS estimates are statistically distinguishable from OLS estimates, indicating an omitted variables bias in the single equation model.