The effect of sibling size on high school and vocational streaming: Evidence from China

• In China, an increase in siblings (SNincrease) reduces children’s senior high school entrance examination (SHSEE) scores and their likelihood of admission to senior high school (HSchance). • The negative effects of SNincrease on SHSEE and HSchance are stronger for higher-ESCS families and for children in Beijing and Shanghai. • Compared with other regions, the resource dilution from an additional child is more pronounced in higher-ESCS families and in households in Beijing and Shanghai. • Policy recommendations are proposed, focusing on increasing educational subsidies, improving the leave system, and strengthening the protection of women’s employment rights. The resource dilution theory suggests that an increase in the number of siblings (SN increase) reduces the resources available to each child in resource-constrained families, thereby affecting educational outcomes. This study investigates the impact of sibling number on children's streaming to high schools and secondary vocational schools using the matching method. The results show that SNincrease reduces the children's high school entrance examination (SHSEE) scores and the chances of attending high school (HSchance). Specifically, when there is one sibling, the child's SHSEE score reduces by 0.104–0.117 standard deviations, and the HSchance reduces by nearly 4%, compared with those of only children. When there are two siblings, the SHSEE score decreases by 0.204–0.259 standard deviations, and the likelihood of attending high school (HSchance) decreases by 6.7%–9.1%. When there are three siblings, the SHSEE score declines by 0.202–0.282 standard deviations, and HSchance drops by 10.3%–13.2%. The analysis results of moderating effect show that compared to families with lower economic, social, and cultural status (ESCS), SNincrease has a greater negative impact on the SHSEE scores and HSchance of children in families with higher ESCS and families in Beijing and Shanghai, China. This study conducts a mechanistic analysis from the aspects of family study spaces and teaching materials. Finally, in the context of low fertility rates in China, this study has proposed corresponding policy recommendations from the perspectives of increasing educational subsidies, improving the leave system, and strengthening the protection of women's employment rights.