In 2008, about fifteen million people used marijuana as recently as that past month. For an industry to begin with an initial market of that number would be remarkable. To put that number in perspective, Apple only sells more iPods than that in one fiscal quarter of the whole year: the October through December quarter or the holiday season. The idea that fifteen million people use marijuana monthly while it is illegal would indicate a strong likelihood that if it were legal, companies would form to take advantage of possible profits to be made.
If marijuana were legalized, new businesses would be formed and with them, thousands of new jobs. As noted above, marijuana already has a proven market of at least fifteen million Americans to sell to. Of course this would increase to even more because there no longer is the fear of legal issues associated with smoking marijuana. As a result, companies and businesses would spring up to make money off of the demand for marijuana. These companies could be producing marijuana, selling marijuana to the public, or even selling marijuana accessories for consumption (e.g. bongs, rolling papers, etc.), just to name a few. Larger corporations would form to become the manufacturers of marijuana, employing thousands upon thousands of people to work. This could be compared to being what R.J. Reynolds is to tobacco for marijuana. On another note, the timber industry is not doing so well today, but with the legalization of marijuana comes the ability to produce hemp. This industry will also create more jobs while replacing an industry that is on the decline.
Some may argue that some people have been growing at their own houses for years and thus question the coming of huge corporations into existence. The production costs for underground marijuana growth, including expensive lamps and sometimes generators, are high but are easily overcome in a market of prohibition because people are willing to pay high prices for something that is illegal and not ostentatiously marketed. Were marijuana to be legalized, the created corporations would cause transaction costs to crumble and as a result, people would not require the services of those who grow and sell their own cannabis. In turn, they would not be able to cover their overhead, or production costs, and as such their business would fail.
Transaction costs: the costs of collecting information about products and transporting goods and people geographically or between markets.
source: http://www.unc.edu/depts/econ/byrns_web/EC434/EC434ClassNotes/Lecture_01_HET.htm
