Legalizing marijuana for recreational use has been a hot political topic in recent years. Different conclusions have been drawn from the literature on this subject, but one conclusion is that the tactic is an effective instrument in combating the black market. On the other side, it has also been demonstrated that it has a negative effect on neighbouring regions that still view marijuana as an illicit drug. 

This study examines the evidence of any causal link between the legalization of marijuana for recreational use and its consequences on neighbouring regions. The legalization of marijuana in Washington state in 2012 and spillover effects on drug-related crime rates in British Columbia served as the foundation for this study. With the help of nine Canadian provinces, a synthetic British Columbia has been created that attempts to simulate how crime rates may have developed had Washington not legalized marijuana. 

The legalization of marijuana has had both positive and negative spillover impacts on the neighbouring territory, according to empirical data. As a "gateway" substance, marijuana possession rates rose after the implementation of the policy. Results on the supply side show that because of increased competition and legal supply from the neighbouring region, marijuana suppliers are switching to other drugs. This essay also addresses other potential social effects of marijuana legalization, such as a decline in the prevalence of sexual assault and marijuana possession among young people. Based on the empirical data, the study offers improvements in aiding neighbouring regions who are considering the implementation of RML in creating preventative measures against illicit usage of marijuana.