In states that have legalized marijuana revenue collections have exceeded initial estimates, says the study. Colorado, which anticipated $70 million in marijuana tax collections per year, will likely exceed $140 million this year. In Washington, sales are averaging more than $2 million a day with revenue potentially reaching $270 million per year. "If all states legalized and taxed marijuana, states could collectively expect to raise between $5 billion and $18 billion per year."
The study points out that large numbers of people are using marijuana, regardless of whether or not it is legal, Christopher Ingraham reports for The Washington Post. More than "13 percent of Americans 12 and older—35 million people—used marijuana in 2014. And 4.2 million of them met criteria for substance abuse or dependence," according to a National Survey on Drug Use and Health. "We're already paying the social cost of marijuana abuse, in other words. Increased tax revenues could help offset those costs."