E L MODELO DE LA COMPLEJIDAD

This paper provides new evidence on the heterogeneous effects of education on crime, overcoming the endogeneity problem that exists between education and crime by making use of twin data contained in detailed Danish Register Data. The paper first confirms a causal link between edu- cation and crime in Denmark, finding significant negative effects of education on an individual’s probability of conviction for total and violent crimes, with marginally significant effects for prop- erty crimes. In the preferred baseline specification, an additional year of education significantly reduces the probability of conviction as an adult for any crime by 14%, for a property crime by 12%, and for a violent crime by 19% for males. The effects of education on adult crime are largely unchanged controlling for whether an individual was convicted of a crime as a juvenile.

Heterogeneous effects are then examined. Family factors, measured by parental education, are found to be important for the effects of education on crime for children, with large crime reduction seen for children of low educated families and virtually no effects on crime seen for children with both parents highly educated. Environmental factors, measured as growing up in a high or low crime neighborhood, have much less impact on the effects of education on crime. Examining how the effects of education on crime differ across crime types reveals education can also reduce traffic related alcohol, sexual, and firearms crimes. Consistent with past literature, the completion of high school is found to reduce criminal propensity for all crime types for male twins, while for female twins, the completion of high school is found to significantly increase the probability of conviction for total and property crimes. Contrary to expectations, the completion of vocational training after lower secondary education is found to have no crime reducing effects for males, while, consistent with expectations, additional university education past high school is found to have no significant crime reducing effects both for males and females.

Due to the potential bias introduced by the presence of DZ twins, and following Conley et al. (2006) and Holmlund et al. (2008), closely spaced siblings are used to account for the presence of these DZ twins. Imputed effects for identical twins remain similar, in terms of magnitude, to the effects of education on crime found and, in most cases, statistically significant. Additionally, the environment twins were raised in is explored in great detail, ensuring the environmental component of twins’ development is the same. Education is found to also reduce an individual’s probability of incarceration, eliminating concerns that the effects of education on crime seen are not due to

reduced criminality but perhaps something particular in the use of conviction data. Similar effects of education on crime are found when excluding twins with large differences in education, limiting concerns that the findings are driven by a few potentially outlying twins. Direct estimation of the reverse causality between education and crime reveals that while juvenile crime does lead to lower educational attainment as a youth, the effects are much smaller than has previously been found, and are not large enough to explain the entire relationship seen between education and adult crime.

While on the whole, the estimated effects of education on crime using Danish twin data are in line with previous research, this paper improves on existing studies, which predominantly examine changes in compulsory schooling laws, by estimating heterogeneous effects of education on crime which are representative of the entire population while, at the same time, netting out inherent common factors between twins which is crucial to identifying causal effects of education on crime. One obvious concern is that the twins analyzed are unique and not representative of the general population. However, OLS results for twins are comparable not only to the non-twin sibling population, but also to the entire non-twin Danish population as well.34 _{This is indicative that}

the effects of education on crime found are representative at least of the Danish population. From a policy perspective, the findings of this paper reveal not only the overall importance of education in terms of crime reduction, particularly for the completion of high school, but also the importance of family background in the crime reducing capabilities of education. For children of low educated parents, it appears to be extremely beneficial to motivate additional schooling as for these individuals, levels of education obtained can be less than is socially optimal. The high crime reduction from children of low educated families also highlights the importance of the intergenerational transmission of education, as while individuals from low educated families experience large crime reduction from additional education, they may be more likely follow in the educational footsteps of their parents and fail to benefit from the crime reducing capabilities of education. This may be of concern even in Nordic countries, where most intergenerational estimates find that an additional year of parental education increases the education of their children by around 0.1 years (Holmlund et al. 2011). Encouraging individuals from low educated families to remain in education, as well as to avoid engaging in juvenile crime, could offer an effective way to not only reduce longer term educational inequality but also reduce criminality on the whole. The

heterogeneous effects outlined reveal the importance of accounting for differences across individuals when estimating the crime reducing capabilities of education, and further research is required to identify precise mechanisms behind these differences.