Young people convicted of drug charges are at higher risk of never attending college at all, thanks in part to a law blocking federal financial aid following a drug conviction, according to research published by the National Bureau of Economic Research this month.

Cornell University assistant professors Michael Lovenheim and Emily Owens analyzed data in a longitudinal survey and found that a 1998 amendment to the Higher Education Act, which prohibits students with drug convictions from obtaining Pell grants or other federally subsidized student aid for up to two years, often prevented those from ever attending college at all. Youth from urban areas whose mothers didn’t go to college were most at risk, they found.

“Importantly, we did not find that the law deterred young people from committing dug felonies nor did it substantively change the probability that high school students with drug convictions graduated from high school,” the paper said.