本研究探討家庭中子女生育間隔與教育成就的關係。生育間隔是父母能以較低成本控制的家庭結構變數，若能了解如何調整生育間隔可增進子女未來發展，則有助於父母進行更縝密的生育規劃。本研究使用1999至2018年的「家庭動態調查」數據，並以多胞胎作為工具變數來處理生育間隔的內生性問題。結果顯示，生育間隔對年長子女的教育成就有正面影響：年齡差距增加一年，取得大學學歷的機率平均增加2.7%；對年幼子女則無顯著影響。此外，生育間隔在不同年代中有不同方向的效果，反映了生育間隔發揮效果的管道在早期社會與現代頗有差異。

This study investigated how birth spacing affects children’s educational achievement using Panel Study of Family Dynamics (PSFD) data for 1999–2018. We converted the panel data into a structure of sibling pairs to estimate the effect of birth spacing on the educational achievements of both older and younger siblings. To account for the endogeneity of birth spacing, we used multiple births as the instrument. Our two-stage least squares (2SLS) estimates indicate that birth spacing positively affects the educational achievement of older siblings. A one-year increase in age difference raises the likelihood of children obtaining a college degree by approximately 2.7%, but spacing has no significant effect on younger siblings. Furthermore, by distinguishing the birth years of the samples, we found that the effects of birth spacing were in opposite directions in different generations. This suggests that the channels through which birth spacing affects educational outcomes vary significantly between early and modern societies.