@airtime143 I copied and responded over here as I thought this was a more appropriate thread for this conversation.
I think there would be some increase in usage from people that didn't want the risk associated with Cannabis when it was illegal. My best guess is that they will not become regular users and be more like someone that goes to Denver for a fun weekend but doesn't wake n bake every day.
There will still be a black market, but my guess is it will be smaller and more localized, especially in places where home growing is legal, people that are capable of growing might sell to friends. Instead of buying from a bigger dealer they would just keep their same small market and produce the product they need instead of paying for it.
The group that gets hurt the most by this is the cartel, but I do not think it will stop them from growing and selling black market but a lot of people, especially those that do not use a lot, will just go to the store to buy it because it is legal and safe.
I am not sure how it effects other drugs in any way. People that use those drugs still will. I don't think it would cause some flood of alternative drugs if there isn't some mass increase in demand.
My personal opinion is that legalization takes a lot (not all) of the money out of the black market and creates businesses, jobs, and tax revenue. All good things considering that we are talking about a relatively harmless plant.
The one aside that I find interesting is that may actually harm the alcohol industry in some ways if people realize that they can still take the edge off and not have to deal with the hangover or the negative health effects of drinking.
The positives certainly outweigh the negatives.