The War on Drugs locked up thousands of black men, and a new study finds that it may have also locked many out of the college classroom—and all the benefits that come with a college degree.

There was a time when black men’s college enrollment was gaining ground, as compared to white men’s. From 1980 to 1985, college enrollment among black men ages 18 to 24 grew slightly faster than it did for their white peers.

However, the upward trend started to reverse for black men after the passage of the Anti–Drug Abuse Act of 1986. According to the study, the probability a black man would enroll in college declined by 10 percent due to the passage of the law, from 22 percent to 20 percent, after researchers controlled for other factors, such as changes in the state-level unemployment rates and the costs of college. The study, written by the University of California, Berkeley professor Tolani Britton, appears to be the first to establish a direct link between ’80s drug laws and college achievement.

Decreased college enrollment has life-long consequences. Only 24 percent of prisoners have some college education, compared with 48 percent of the general public. Without a college degree, the odds of obtaining stable, well-paying employment are even lower; bachelor’s degree holders earn $21,632 more a year than individuals with only a high-school diploma, according to the Bureau of Labor Statistics.