Recent Developments in Intergenerational Mobility

Economists and social scientists have long been interested in intergenerational mobility, and documenting the persistence between parents and children's outcomes has been an active area of research. However, since Gary Solon's 1999 Chapter in the Handbook of Labor Economics, the literature has taken an interesting turn. In addition to focusing on obtaining precise estimates of correlations and elasticities, the literature has placed increased emphasis on the causal mechanisms that underlie this relationship. This chapter describes the developments in the intergenerational transmission literature since the 1999 Handbook Chapter. While there have been some important contributions in terms of measurement of elasticities and correlations, we will focus primarily on advances in our understanding of the forces driving the relationship and less on the precision of the correlations themselves.Intergenerational Transmission, Educational Mobility

From the Cradle to the Labor Market? The Effect of Birth Weight on Adult Outcomes

Lower birth weight babies have worse outcomes, both short-run in terms of one-year mortality rates and longer run in terms of educational attainment and earnings. However, recent research has called into question whether birth weight itself is important or whether it simply reflects other hard-to-measure characteristics. By applying within twin techniques using a unique dataset from Norway, we examine both short-run and long-run outcomes for the same cohorts. We find that birth weight does matter; very small short-run fixed effect estimates can be misleading because longer-run effects on outcomes such as height, IQ, earnings, and education are significant and similar in magnitude to OLS estimates. Our estimates suggest that eliminating birth weight differences between socio-economic groups would have sizeable effects on the later outcomes of children from poorer families.

Fast Times at Ridgemont High? The Effect of Compulsory Schooling Laws on Teenage Births

Research suggests that teenage childbearing adversely affects both the outcomes of the mothers as well as those of their children. We know that low-educated women are more likely to have a teenage birth, but does this imply that policies that increase educational attainment reduce early fertility? This paper investigates whether increasing mandatory educational attainment through compulsory schooling legislation encourages women to delay childbearing. We use variation induced by changes in compulsory schooling laws in both the United States and Norway to estimate the effect in two very different institutional environments. We find evidence that increased compulsory schooling does in fact reduce the incidence of teenage childbearing in both the United States and Norway, and these results are quite robust to various specification checks. Somewhat surprisingly, we also find that the magnitude of these effects is quite similar in the two countries. These results suggest that legislation aimed at improving educational outcomes may have spillover effects onto the fertility decisions of teenagers.

Older and Wiser? Birth Order and IQ of Young Men

While recent research finds strong evidence that birth order affects children's outcomes such as education and earnings, the evidence on the effects of birth order on IQ is decidedly mixed. This paper uses a large dataset on the population of Norway that allows us to precisely measure birth order effects on IQ using both cross-sectional and within-family methods. Importantly, irrespective of method, we find a strong and significant effect of birth order on IQ, and our results suggest that earlier born children have higher IQs. Our preferred estimates suggest differences between first-borns and second-borns of about one fifth of a standard deviation or approximately 3 IQ points. Despite these large average effects, birth order only explains about 3% of the within-family variance of IQ. When we control for birth endowments, the estimated birth order effects increase. Thus, our analysis suggests that birth order effects are not biologically determined. Also, there is no evidence that birth order effects occur because later-born children are more affected by family breakdown.

Under Pressure? The Effect of Peers on Outcomes of Young Adults

A variety of public campaigns, including the “Just Say No” campaign of the 1980s and 1990s that encouraged teenagers to “Just Say No to Drugs”, are based on the premise that teenagers are very susceptible to peer influences. Despite this, very little is known about the effect of school peers on the long-run outcomes of teenagers. This is primarily due to two factors: the absence of information on peers merged with long-run outcomes of individuals and, equally important, the difficulty of separately identifying the role of peers. This paper uses data on the population of Norway and idiosyncratic variation in cohort composition within schools to examine the role of peer composition in 9th grade on longer-run outcomes such as IQ scores at age 18, teenage childbearing, postcompulsory schooling educational track, adult labor market status, and earnings. We find that outcomes are influenced by the proportion of females in the grade, and these effects differ for men and women. Other peer variables (average age, average mother’s education) have little impact on the outcomes of teenagers.

Under Pressure? The Effect of Peers on Outcomes of Young Adults

A variety of public campaigns, including the “Just Say No” campaign of the 1980s and 1990s that encouraged teenagers to “Just Say No to Drugs”, are based on the premise that teenagers are very susceptible to peer influences. Despite this, very little is known about the effect of school peers on the long-run outcomes of teenagers. This is primarily due to two factors: the absence of information on peers merged with long-run outcomes of individuals and, equally important, the difficulty of separately identifying the role of peers. This paper uses data on the population of Norway and idiosyncratic variation in cohort composition within schools to examine the role of peer composition in 9th grade on longer-run outcomes such as IQ scores at age 18, teenage childbearing, postcompulsory schooling educational track, adult labor market status, and earnings. We find that outcomes are influenced by the proportion of females in the grade, and these effects differ for men and women. Other peer variables (average age, average mother’s education) have little impact on the outcomes of teenagers.Peer Effects, Education

Small Family, Smart Family? Family Size and the IQ Scores of Young Men

How do families influence the ability of children? Cognitive skills have been shown to be a strong predictor of educational attainment and future labor market success; as a result, understanding the determinants of cognitive skills can lead 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, we instrument for family size using twin births and sex composition. IV estimates using sex composition as an instrument show no negative effect of family size; however, IV estimates using twins imply that family size has a negative effect on IQ. Our results suggest that effect of family size depends on the type of family size intervention. We conclude that there are no important negative effects of expected increases in family size on IQ but that unexpected shocks to family size resulting from twin births have negative effects on the IQ of existing children.

Why the Apple Doesn't Fall Far: Understanding Intergenerational Transmission of Human Capital

Parents with higher education levels have children with higher education levels. However, is this because parental education actually changes the outcomes of children, suggesting an important spillover of education policies, or is it merely that more able individuals who have higher education also have more able children? This paper proposes to answer this question by using a unique dataset from Norway. Using the reform of the education system that was implemented in different municipalities at different times in the 1960s as an instrument for parental education, we find little evidence of a causal relationship between parents' education and children's education, despite significant OLS relationships. We find 2SLS estimates that are consistently lower than the OLS estimates with the only statistically significant effect being a positive relationship between mother's education and son's education. These findings suggest that the high correlations between parents'and children's education are due primarily to family characteristics and inherited ability and not education spillovers.

Recent Developments in Intergenerational Mobility

Economists and social scientists have long been interested in intergenerational mobility, and documenting the persistence between parents and children’s outcomes has been an active area of research. However, since Gary Solon’s 1999 Chapter in the Handbook of Labor Economics, the literature has taken an interesting turn. In addition to focusing on obtaining precise estimates of correlations and elasticities, the literature has placed increased emphasis on the causal mechanisms that underlie this relationship. This chapter describes the developments in the intergenerational transmission literature since the 1999 Handbook Chapter. While there have been some important contributions in terms of measurement of elasticities and correlations, we focus primarily on advances in our understanding of the forces driving the relationship and less on the precision of the correlations themselves.