Here's a study that supports what we have been hearing from people. People do not want to buy illegal marijuana from the street if they have a choice about it. In fact, consumers of marijuana will pay more for legal marijuana than the other stuff.
Why would someone pay more for legal marijuana than the other stuff? We hear that people are willing to pay more for the quality, reliability, and good karma that they get from regulated, tested legal marijuana. So legalizing marijuana gives consumers a better product, gives states more tax income to spend on schools and firefighters, and starves the cartels of income. Kinda makes sense, no?