The interaction among siblings has played an important role in obtaining access to education for individuals. In the background of the universal two-child policy, it will undoubtedly come to the conclusion that having a second child is not conducive to children’s education, judging from the resource dilution effect. However, education, as a result of the joint influence of family, school and society, is naturally affected by the interaction among people. As the most direct and lasting interpersonal bond in the family system, siblings are closely related to individual education acquisition. In fact, due to the rapid change of knowledge between generations, the study of individuals is often carried out through siblings’ counseling or social training institutions, rather than through continuous counseling by parents. One question arises: To what extent is individual’s education affected by the interaction among siblings within the family? More specifically, how does the elder sibling going to college affect the younger sibling’ s access to higher education?

Based on the two-wave data of Chinese Household Income Project（CHIP）in 2013 and 2018, this paper evaluates the impact of the elder sibling going to college on the younger sibling’s access to higher education. This paper finds that: （1）The elder sibling going to college has a significant positive impact on the younger sibling’ s access to higher education, and the impact is stronger in two-child families and urban families, showing an educational spillover effect among siblings.（2）The spillover effect is related to the sibling structure and family factors. Specifically, it will be stronger when the elder sibling is the eldest, they have the same gender, and their age gap is 4-6 years. And marriage breakdown and parent-child interaction will also affect it to a certain extent.（3）A further analysis of potential mechanisms reveals that the knowledge transfer and role model effects from the elder sibling to the younger sibling perform certain key functions.（4）The spillover effect could also be further transmitted to the younger sibling’s employment. The individual with an elder sibling going to college is more likely to get a job and participate in state-owned departments.

The conclusions of this paper reveal that the elder sibling going to college not only has great contribution to their own development, but also makes the younger sibling benefit from it, which provide a new perspective for understanding the universal two-child policy. Therefore, it is crucial to pay attention to education, especially the education of the elder sibling. It is not an appropriate choice for the elder sibling to end their studies and then take part in the labor market early. In terms of policy implications, on the one hand, we should take a comprehensive assessment about having a second child on the family, not only the resource dilution effect, but also the positive impact of the interaction among siblings such as companions, mutual aids and partners of supporting parents. On the other hand, the formulation of policies to promote fertility desire for two-child needs to consider the issue of“birth choice”. And the family with stable marriage, parent-child interaction, and an elder child of moderate age may be more suitable as incentive targets.