Factors driving the diffusion of medical marijuana legalisation in the United States

摘要

In the past 20 years, the drive to legalise medical marijuana (cannabis) has gained national attention with the public and policy makers. Beginning in 1996 states started implementing MMLs (medical marijuana laws), and by the end of 2015, 23 states and the District of Columbia had adopted laws legalizing marijuana use for medical purposes. We find that measures of policy diffusion and political culture are important drivers of adoption. However, the relative effects of positive pressure from neighbouring states and negative pressure from the ideological distance between adopting and non-adopting states is such that complete diffusion is unlikely.