A new study authored by economists at three U.S. universities shows no link between medical marijuana laws and increased teen cannabis use.

The study authors used statistics from the National Youth Risk Behavior Survey (YBRS) from the years 1993 to 2009 and studied how they related to the 13 states that legalized medical marijuana in that time period.

“There is anecdotal evidence that medical marijuana is finding its way into the hands of teenagers, but there’s no statistical evidence that legalization increases the probability of use,” Daniel I. Rees, a professor of economics at the University of Colorado Denver, said in a written statement.

The study has been made available by the nonprofit Institute for the Study of Labor based on Bonn, Germany. The research is not peer-reviewed.

The more regulated the sale of marijuana is, the less likely teens will be able to get it. It’s been said many times before, and sums up the entire controversy quite nicely: drug dealers don’t check I.D.

- Joe Klare