Does liberalizing cannabis laws increase cannabis use?

A key question in the ongoing policy debate over cannabis' legal status is whether liberalizing cannabis laws leads to an increase in cannabis use. This paper provides new evidence on the impact of a specific type of liberalization, decriminalization, on initiation into cannabis use. Our identification strategy exploits variation in the timing of cannabis policy reforms and our estimation framework marries a difference-in-difference approach with a discrete time duration model. Our results reveal evidence of both heterogeneity and dynamics in the response of cannabis uptake to decriminalization. Overall, we find that the impact of decriminalization is concentrated amongst minors, who have a higher rate of uptake in the first five years following its introduction.