Birth Spacing and Sibling Outcomes

A large body of work in economics and other disciplines has investigated the relationship between family structure- including birth order, family size, and sibling composition- and children's outcomes. However, the age difference between siblings (spacing) has received much less attention in the economic literature, despite the fact that child spacing "may well be the most important aspect of fertility differentials in low-fertility societies" (Wineberg and McCarthy 1989). In this paper, we investigate the effects of birth spacing on one important later-life outcome: academic achievement as measured by performance on the Peabody Individual Achievement Tests for math and reading.