School is a formative time in a child’s life, and policymakers should probably take notice because the age parents enroll their child in kindergarten could set them up for failure. Researchers from Duke University collaborated with Hanyang University in South Korea to better understand why some students are more likely to drop out of school than others. The study, which will be published in the American Economic Journal-Applied Economics, reveals a new link between the age children start school, and drop out and commit crimes.

“This research provides the first compelling evidence of a causal link between dropout and crime,” said the study’s lead author Philip J. Cook, a professor in Duke’s Sanford School of Public Policy, in a press release. “It supports the view that crime outcomes should be considered in evaluating school reforms. Dropouts are greatly over-represented in prison, so we know there is a strong association between dropping out and crime. But to establish causation requires an experiment. My analysis takes advantage of nature’s experiment associated with birth date.”

Researchers monitored American students who were born 60 days before and 60 days after the school cutoff date, which was Oct. 16. Children had to turn 5 before they were eligible to start kindergarten. Studies have shown parents will hold their child back if their birthday falls right before the cut off date; if their birthday is Oct. 10, for example. Their parents think they’re giving their child a social and academic advantage by making them “old-for-grade” through delayed enrollment.

While they excel over their younger classmates in every single measure of school performance, their leverage dies out by their 16th birthday. Old-for-grade students were about 30 percent less likely to engage in delinquent behavior because they were more physically and mentally mature than their schoolmates. But that dynamic shifts at 16, making them more likely to drop out and get convicted of a felony by sometime around 20 years old.

“Should you redshirt your kid?” Cook said. “Well, on the one hand, he’ll do better while he’s in school and is less likely to become delinquent. On the other hand, he’ll be more likely to drop out before graduation, and bad things may follow that. Even something as crude as a regulation that requires a kid stay in school to a fixed age, whether he wants to or not, has a considerable effect on criminal activity.”

Parents are more likely to academically redshirt their son over their daughter, and it is overall more common among white parents than African-Americans. The likelihood of an old-for-grade student dropping out and committing a serious crime increases 3.4 times for children of unwed mothers, and 2.7 times if their mothers were also high school dropouts.

“People say there is no point keeping a kid in school who doesn’t want to be there because he won’t learn anything and he’ll be disruptive,” Cook said. “My findings suggest that intuitive argument is not entirely correct. Even students who would rather drop out can benefit from staying in school when they are required to do so. Otherwise they are prime candidates for recruitment into a life of crime.”

Source: Cook PJ and Kang S. American Economic Journal-Applied Economics. 2015