A growing number of studies find that birth order affects educational attainment and labor market outcomes: younger siblings within the same family have consistently worse adult economic outcomes than their elder siblings.In this paper, we investigate when these birth order differences appear and how they evolve from birth to adolescence. We document differences by order of birth in development measures and standardised tests scores from toddlerhood to adolescence using U.S. data from the Children of the NLSY79.As early as age one, later-born children score lower than their older siblings. The birth order gap increases until school entry and remains substantial thereafter. Parental behavior matches the pattern: mothers are more likely to take risks during pregnancy and are less likely to breastfeed their younger children.Furthermore, parents provide less cognitive stimulation for their later-born children. Variations in parental behavior can explain a large portion of the birth order differences in test scores before school entry. Contrary to popular belief, we do not find any birth order effect on temperament and other measures of soft skills, nor differences in parental emotional support by order of birth.Taken together, our findings suggest that a plausible explanation for the negative relation between birth order and educational achievement is a broad shift in parenting, especially with respect to parents' ability to foster early cognitive development. Significant variation in parental behavior during pregnancy and the first few years of life, as well as the absence of any differences in the quality of emotional support, are consistent with the explanation that parents are choosing to relax what they might deem as non-essential rearing needs for their later-born children.For most parents, it is probably not difficult to understand how and why one's parenting focus and behavior may change with his/her later-born children. Lessons from past experiences and additional constraints on time, resources, and attention necessitate adjustments in their attitudes and beliefs about what may be possible to accomplish as parents. These broad shifts in parental behavior appear to set later-born children on a lower path for cognitive development and academic achievement, with lasting impact on adult outcomes. ABOUT THE AUTHORSJee-Yeon K. Lehmann is a manager at the Analysis Group Inc., where she specializes in the application of microeconomic theory, econometrics, and statistical methods to complex matters in the areas of labor economics, antitrust, health care, and intellectual property. Prior to joining Analysis Group in 2014, she was an assistant professor of economics at the University of Houston. Her academic research focuses on determinants of inequalities and discrimination in the labour market and in the legal system. She received her PhD from Boston University in 2012 Email: jee-yeon.lehmann@analysisgroup.com.Ana Nuevo-Chiquero is a Lecturer at the School of Economics at the University of Edinburgh and an IZA Resea...

While survey data supports a strong relationship between personality and labour market outcomes, the exact mechanisms behind this association remain unexplored. We take advantage of a controlled laboratory set-up to explore whether this relationship operates through productivity. Using a realeffort task, we analyse the impact of the Big Five personality traits on performance. We find that more neurotic subjects perform worse, and that more conscientious individuals perform better. These findings suggest that at least part of the effect of personality on labour market outcomes operates through productivity. In addition, we find evidence that gender and university major affect this relationship.