Javier Martinez uses a sign to advertise for LoHi Cannabis Club dispensary as an estimated 10,000 people were expected to gather for a 4/20 marijuana rally in Civic Center Park April 20, 2012 in Denver, Colorado. - 

On Tuesday, voters in Colorado and Washington approved different versions of legalized recreational marijuana. Federal law still prohibits the possession, use and sale of the drug for any purpose -- medical or recreational.

Sure, this story is about culture and lifestyle, but it's also about economics. The idea is that by taking underground drug-dealing and making it legitimate, you grow an industry in the light of day that can be regulated and taxed.

Yet, Mark Kleiman, a professor of public policy at UCLA and coauthor of the book Marijuana Legalization: What everyone needs to know, says "the most likely result is no industry at all because the federal government will not permit it."

Though according to Kleiman, in Colorado, where the new law allows individuals to cultivate and give marijuana away for free, an informal market could crop up which would be very difficult for federal officials to prevent.

Follow Jeff Horwich at @jeffhorwich