Abstract

Joint work with Petter Lundborg, Astrid Rasmussen, and Julius Ilciukas

This paper examines how only children fare in school using fertility treatment success as natural experiment. With administrative data from Denmark, we first show that in vitro fertilization (IVF) treatments provide ample exogenous variation in the likelihood to have siblings. With IVF treatment success as legitimate instrumental variable (IV), we then estimate the causal effect of being the only child on school performance. Our preliminary results indicate that, when it comes to the school outcomes we measure, there is little value in having siblings; that is, first-born children with and without siblings (for exogenous reasons) do equally well in terms of cognitive and noncognitive skills.