After legal recreational marijuana dispensaries opened in Colorado on Jan 1st, the state's data on marijuana use was examined closely by other states. They discovered that even prior to legalization, Denver teens were using marijuana at nearly twice the national average. With the drug now becoming readily available, one can expect these numbers to increase

I see how legalization will lead to increased usage--naturally, most individuals are disinclined to engage in illegal activity, regardless of the rationale or lack thereof behind its illegality. However, I am failing to make the connection between your chart and your title; what is the negative effect of legalized marijuana? Thanks.

Hi, Anthony. My argument is framed around the point that while the drug is now legal for adult Colorado citizens, it still remains a criminal act for children and teens to consume marijuana. Any increased consumption by teens, can be considered negative from a strictly legal perspective.

Ah, I se your point. In that case, it would be prudent to consider the current legislation regarding its underage usage, and the effect this change has on juvenile detention and other measures of minor criminality. That is, I presume now that marijuana is legal for Colorado adults, the criminality of usage by teenagers will correspondingly be diminished, as compared to when it was entirely illegal. Given that, as your chart evinces, large (and growing) numbers of Colorado teens were already using marijuana before legalization, it would be interesting to see if the increase in teen usage with legality, and the resulting criminal charges, outweighs the diminished criminality of underage use. It might in fact be the case that the positive effect of this lessened severity supersedes the negative effect of increased underage use. Only time will tell, but it most certainly is a curious consideration worth investigating. Thanks for explaining.

I agree Anthony. I believe only time will tell whether legalization will lead to increased underage marijuana use in Colorado. Marijuana is, and has been, very available for teens for quite some time in Denver and I'm not sure if legalization will make it considerably easier for them to obtain marijuana. Personally, I believe an initial spike (as shown by the graph) in underage use will continue for several years post legalization. However, as the marijuana market becomes regulated and the criminality measures surrounding marijuana are diminished, teens may be less inclined to partake in the "thrill" of smoking pot.