A contrasting report: http://www.rmhidta.org/html/2016%20FINAL%20Legalization%20of...

There are indeed significant changes in some marijuana-related statistics. The Cato institute report has selected indicators that are relatively stable and do not show these effects. It does not discuss the limitations of the data, discuss data sources that were considered but not used, or include illustrative anecdotes. It can be summarized as "we carefully picked these graphs that didn't show anything, and we still can't rule out any effects of legalization".