birth order effects occur because later-born children are more affected by family breakdown. …While recent research finds strong evidence that birth order affects children's outcomes such as education and earnings … Norway that allows us to precisely measure birth order effects on IQ using both cross-sectional and within-family methods …

How do families influence the ability of children? Cognitive skills have been shown to be a strong predictor of … to a better understanding of children's long run outcomes. This paper uses a large dataset on the male population of … Norway and focuses on one family characteristic: the effect of family size on IQ. Because of the endogeneity of family size …

birth order effects occur because later-born children are more affected by family breakdown. …While recent research finds strong evidence that birth order affects children's outcomes such as education and earnings … Norway that allows us to precisely measure birth order effects on IQ using both cross-sectional and within-family methods …