3.3 Crime
Rates of conviction in New Zealand peak amongst young people, and in particular amongst young males (Spier 2002). The 2001 census of prison inmates showed that almost two-thirds of prison inmates had had their first conviction for any offence while in their teens (Department of Corrections 2003).
From the Christchurch HDS, Fergusson et al (2002) investigate the association between leaving school without qualifications and three self-reported measures of juvenile offending between the ages of 18 and 21. These measures are a history of violent offending, property offending, and being convicted of an offence. Almost 12% of sample members had a conviction between ages 18 and 21. To account for factors occurring before the study members sat School Certificate, and which might confound the relationship between education and juvenile offending, Fergusson et al control for a wide range of background variables. In particular, they control for gender, for deviant behaviours and conduct disorders in childhood, for deviant peer affiliations, for parents’ criminal behaviour, and for level of family disadvantage. After controlling for these factors there was no persistent link between juvenile offending and leaving school without qualifications. Young people who were already at risk of later crime also tended to perform poorly at school; these outcomes simply shared the same predictors.
In contrast, using the Dunedin MHDS cohort, Henry, Caspi, Moffitt, Harrington and Silva (1999) found that the longer that male students (although not female students) stayed at school past the minimum leaving age of 15 years the lower their chances of criminal behaviour in young adulthood. Criminal behaviour was measured by self-reports of criminal offences together with official information on criminal convictions. Furthermore, the relationship between time at school and criminal behaviour was strongest amongst those young men who had demonstrated behaviour and attention problems as young children. These problems are known predictors of anti-social behaviour in later life. The relationships remained significant after controlling for the effects of socio-economic status, IQ, family disruption, and adolescent delinquency. These results suggest a causal link where continued school attendance provides a constraint on criminal behaviour.
Looking further ahead into adulthood, Lochner and Moretti (2001) use the public versions (one percent samples) of the 1960, 1970 and 1980 United States Censuses to identify male prison inmates aged 20-60 and to compare their characteristics with the non-imprisoned male population of the same age. After controlling for age, state of birth, state of residence, cohort of birth, and year effects, they find that years of education are negatively associated with the probability of imprisonment. In particular, they find a marked decline in the probability of imprisonment at 12 years of schooling, which in the United States generally corresponds to graduation from high school. This suggests that there may be a benefit from holding a high school diploma which is more than would be expected from simply completing an extra year of education. Therefore there may a degree of credentialing or signalling in evidence here, similar to that sometimes suggested for the earnings-related benefits of education (Weiss 1995; Collins 1979). To account for unobserved characteristics of criminals, which might be different from those of non-criminals, Lochner and Moretti also use state compulsory schooling laws as an instrument for high school graduation. The resulting IV estimates continue to show a significant inverse relationship between education and imprisonment.
The studies reviewed in this section, and in particular the findings from the Christchurch HDS and Dunedin MHDS, seem to show conflicting results. However, this is not necessarily the case. In a review of the effects of education on crime, Witte (1997) concludes that studies which measure education by means of test scores or the receipt of qualifications (of which Fergusson et al is an example) generally find that these variables are not significantly related to future crime. However, those smaller number of studies which have the use of time as an explanatory variable (of which Henry et al is an example) generally find that both time spent at school and, to a slightly lesser extent, time spent working, are associated with a significantly lower level of criminal activity. Inactive teenagers are those at highest risk of committing crimes. One interpretation of this association is that schooling has a protective function, regardless of any qualifications obtained, simply by keeping young people occupied and off the streets. Another, however, might be that young people with criminal tendencies would rather be on the streets committing crimes than working or at school. Lochner and Moretti’s IV study suggests that increased education reduces the probability of going to prison for males in the United States, at least for students compelled to stay in school through compulsory schooling changes. It is difficult to know, however, how much this result can be generalised to contemporary New Zealand since, for example, their study includes people who were in prison more than 40 years ago, and were at school some years before this.
3.4 Fertility and sexual risk-taking
New Zealand has one of the highest teenage birth rates in the industrialised world, trailing only the United States and the United Kingdom (Statistics New Zealand 2001). From the Christchurch HDS, Fergusson and Woodward (2000) examine the effect of teenage pregnancy on educational achievement, rather than the other way round. However, data from this study show that 32% of young women who left school without qualifications had become pregnant before age 18, compared to only 4% of women who had school qualifications. These figures are not, however, adjusted for any potentially confounding individual or family antecedents of teen pregnancy; nor do they take into account which came first: teen pregnancy or gaining school qualifications.
Manlove (1998) investigates potential confounding, and the timing of pregnancy, when examining the relationship between dropping out of high school and teenage motherhood (defined in this study as a pregnancy prior to the age of expected high school completion). She uses data from the United States National Education Longitudinal Study of 1988 – a sample of eighth-graders (14 year olds), who were resurveyed in 1990, 1992 and 1994. Dropping out of school was found to have a significant effect on the risk of teenage motherhood among White and Hispanic, but not Black, women. The risk of teenage motherhood among White and Hispanic dropouts was one-and-a-half times that of women who stayed in school, despite controlling for a wide range of potentially confounding family, individual, and school and classroom characteristics (including grades and test scores). Moreover, the longer that White and Hispanic students remained in school the lower their risk of having a school-age pregnancy. High grades in the first year of high school, high scores on maths and English tests, and plans for future training or study were all significantly associated with a reduced risk of teenage motherhood.
These results suggest that staying in school, and perhaps also completing school qualifications, reduces the probability of young women becoming pregnant in their teens. There remains, however, a question about how applicable the results of a United States study on high school dropouts is to New Zealand.
3.5 Welfare dependence
Reducing unemployment and other forms of welfare dependence are considered here as potentially wider benefits of education, since they may have costs to individuals and to society that are over and above those of lost earnings and production. Unemployment, for example, might be seen as a poor outcome in its own right, promoting feelings of worthlessness or detachment from society, for example, and may also be a factor linking education to other poor outcomes in adulthood (so that, for example, education may cause unemployment which in turn causes criminal behaviour).
From the Christchurch HDS, Fergusson et al (2002) investigate the association between leaving school without qualifications and being in receipt of a Social Welfare benefit at age 21. At this age, 18% of the cohort was receiving a benefit: 9.3% received an Unemployment Benefit, 4.3% received a Domestic Purposes Benefit, and 5.1% received other types of benefits. Fergusson et al also looked at whether sample members had taken part in any tertiary education or training after they had left school.
To account for factors occurring before the study members sat School Certificate, and which might confound the relationship between education and welfare dependence, and between education and further training, Fergusson et al control for a wide range of background variables, including gender, deviant behaviours and conduct disorders in childhood, childhood IQ and school achievement, and level of family disadvantage. Fergusson et al find a persistent link between leaving school with no qualifications and being on a Social Welfare benefit at age 21. They also find a persistent link between leaving school with no qualifications and not going on to tertiary education or training. This is not necessarily a poor outcome in itself, and is not discussed in the following sections, but it does suggest that poor basic skills may close off the possibility of further investments in education.
Further, more detailed, evidence on the relationship between poor school performance and unemployment is available from the Dunedin MHDS. Caspi, Wright, Moffitt and Silva (1998) find that leaving school with no qualifications, and poor reading achievement at age 15, were predictive of later unemployment. After controlling for a range of individual, family and school variables, measured when participants were aged 15, young people without any School Certificate passes were 17% more likely than others to be unemployed between the ages of 15 and 21, and young people with poor reading skills were 12% more likely than others to be unemployed. Further analysis showed that there was also a benefit to simply staying at school. About a third of the effect of getting School Certificate was accounted for by the corresponding increase in the duration of education, suggesting that young people who did not get School Certificate were at risk for unemployment, in part, because they left school at an earlier age. For the most part, though, not having School Certificate, and having poor reading skills, appeared to have a direct impact on employment in later adolescence.
Looking further ahead into adulthood, Oreopoulos (2003) considers the effect of changes to compulsory schooling laws in the United States, Canada and the United Kingdom on the likelihood of being unemployed. The datasets he uses are different for each country but all include adults aged 25 to 64. Oreopoulos shows that in each of these three countries an additional year of schooling was associated with a reduction in the probability of being unemployed. In addition, in the United States (the only country where this was measured), an additional year of schooling was associated with a reduction in the probability of receiving a welfare benefit.
The results from the New Zealand birth cohort studies, and from the IV study of Oreopoulos (2003), therefore suggest that staying at school and achieving basic school qualifications reduces an individual’s risk both of being unemployed in young adulthood and of being reliant on a welfare benefit.
