I think it is worth mentioning that violent crime and property crime are down more than 10% post-legalization, that the state forecasts $30M in tax revenue, and $2M has already been created for local schools.
I don't have the stats but I read an article from a local news organization that arrests for driving while under the influence of marijuana are up significantly. However, that could be just increased enforcement or awareness by police to look for it than actual incidents of driving while high.
These driving while high statistics are pretty error prone. There is no marijuana breathalyzer. A blood test shows traces of THC in your body from up to 30 days ago. So if you get in an accident and get blood tested and it comes back positive, were you high at that moment? Or a week ago? Or a month ago?
I'm sure the technology will improve. In fact, a "marijuana breathalyzer" (using that term loosly because you would need something that can test for edibles too), is probably a pretty interesting product to bring to market
Very likely, and even if it were not the case you could still have a net decrease in DUIs with an increasing amount of marijuana DUIs.
I am pretty sure there have been some studies that show people under the influence of marijuana are less likely to drive than people under the influence of alcohol so it just depends on whether marijuana is replacing alcohol or not.
A statistically insignificant result is politically significant: it wrecks the 'omg pot smokers will lead to tons of crime' argument some politicians were making.
I wouldn't draw very much from that violent crime factoid. Denver was not exactly the most violent city before legalization, and has its own circumstances, so you wouldn't want to generalize from Denver's example to more violent urban centers like Chicago or New York for example.
Although I absolutely agree that the tax revenue is a great boon.
New York's murder rate is very similar to Denver's, and was actually lower in 2012. Its violent days are long past, and even its bad neighborhoods are as safe from violent crime as its richest 20 years ago:
http://observer.com/2013/05/bloomberg-recalls-upper-east-sid...