Thursday, February 16, 2017

Why are second-born boys more likely to be delinquents?

...we find that second-born boys are substantially more likely to exhibit delinquency problems compared to their older sibling. In particular, involvement with the juvenile justice system is found to be on the order of 40 percent higher than the mean for first-born boys in both Denmark and Florida. Incarceration by age 21 is also found to be 40 percent higher in Denmark. These effects are particularly strong among more severe violent crimes (36 percent). In Florida, similarly large effects are found for suspensions in school (29 percent) but effects on truancy are much more moderate and heterogeneous. We find corroborative evidence when we consider a sample of young adolescents in Denmark where we can measure behavioral problems directly in the form of hyperactivity and measures of conduct problems by age 12.

In terms of mechanisms, we can rule out large classes of explanations. These include worse health at birth (second-born children appear healthier) or in childhood (second-born children have fewer disabilities), schooling decisions including the age of entry and the quality of schools chosen (second-born children attend no worse schools and are more likely to attend pre-kindergarten and daycare) as well as maternal employment (measured by maternity leave) in the first year of life. We do find that maternal employment and the use of daycare is higher for second-borns in years 2-4 compared to older siblings. While it is well known that first-borns have undivided attention until the arrival of the second-born, these results show that the arrival of the second-born child has the potential to extend the early-childhood parental investment in the first-born child and a concomitant bifurcation of parental attention between first- and second-born children.
--Sanni Breining, Joseph Doyle, David Figlio, Krzysztof Karbownik, and Jeffrey Roth, NBER Working Paper 23038, on the importance of parental investment