In November 2012, Colorado and Washington approved ballot initiatives that legalized marijuana for recreational use under state law. Since then, nine additional states (Alaska, Oregon, California, Nevada, Maine, Vermont, Massachusetts, Michigan, and Illinois) plus the District of Columbia have...

By the end of 2016, 28 states had liberalized their marijuana laws: by decriminalizing possession, by legalizing for medical purposes, or by legalizing more broadly. More states are considering such policy changes even while supporters and opponents continue to debate their impacts. Yet evidence...

In November 2012 voters in the states of Colorado and Washington approved ballot initiatives that legalized marijuana for recreational use. Two years later, Alaska and Oregon followed suit. As many as 11 other states may consider similar measures in November 2016, through either ballot...

By the end of 2016, 28 states had liberalized their marijuana laws: by decriminalizing possession, by legalizing for medical purposes, or by legalizing more broadly. More states are considering such policy changes even while supporters and opponents continue to debate their impacts. Yet evidence...