Marijuana never should have been made illegal. It was outlawed because of money, corruption, and racism. The federal government states that marijuana is highly addictive and highly dangerous, but science has proved that they are wrong. The government has no right telling you that you cannot use marijuana, just like they have no right telling you that you cannot drink alcohol, eat at McDonalds, go rock climbing, or sit on the couch and play video games.
Here is a link to a study on the economics of marijuana prohibition and legalization which is very interesting.
http://www.cato.org/publications/whi...ug-prohibition
I don't think the effects will kick in until it is legalized on a federal level, but when it is, I think there will be quite a bit of money generated for the country.