Sandberg John, Rafail Patrick
Milken Institute School of Public Health, Department of Global Health, The George Washington University, 950 New Hampshire Avenue, NW, Washington, DC, 20052, USA,
Demography. 2014 Oct;51(5):1895-931. doi: 10.1007/s13524-014-0331-8.
Measures of children's time use, particularly with parents and siblings, are used to evaluate three hypotheses in relation to the vocabulary and mathematical skills development: (1) the resource dilution hypothesis, which argues that parental and household resources are diluted in larger families; (2) the confluence hypothesis, which suggests that the intellectual milieu of families is lowered with additional children; and (3) the admixture ("no effect") hypothesis, which suggests that the negative relationship between family size and achievement is an artifact of cross-sectional research resulting from unobserved heterogeneity. Each hypothesis is tested using within-child estimates of change in cognitive scores over time with the addition of new children to families.
衡量儿童时间利用情况的指标，尤其是与父母和兄弟姐妹相处的时间，被用于评估与词汇和数学技能发展相关的三个假设：（1）资源稀释假设，该假设认为在大家庭中父母和家庭资源会被稀释；（2）融合假设，该假设表明随着孩子数量增加，家庭的智力环境会降低；（3）混合（“无影响”）假设，该假设认为家庭规模与学业成就之间的负相关关系是由未观察到的异质性导致的横断面研究的产物。每个假设都通过对家庭中新增孩子后随时间变化的认知分数进行儿童内部估计来进行检验。
