Some of my libertarian friends are advocates for legalizing recreational use of marijuana. I’ve asked them if they wonder about unintended consequences — like this.

The report, issued by the Insurance Institute for Highway Safety, said that car accidents reported to police in three states that had legalized marijuana sales—Colorado, Washington, and Oregon—saw 5.2% more accidents than did their neighboring states.

A second study by the group estimated that states that had legalized cannabis saw 6% more insurance collision claims than other states.

But not all studies support the connection.

Last year, a study in the American Journal of Public Health looked at traffic fatalities in Colorado and Washington to find that there was “no significant association” between pot legalization and higher fatalities.

I wonder. Do you?