Marijuana use is not on the rise.
At least, that's the gist of the National Survey on Drug Use and Health done every year by the U.S. Department of Health and Human Services. In 2008 — the most recent data available — 6.1 percent of Americans 12 and older admitted using marijuana in the previous month.
In absolute terms, that number is probably low; after all, this survey asks people to admit to using illegal drugs. But the real significance of the number is that it's steady — it's been hovering right around 6 percent since 2002. Drug researchers say the real percentage may be higher, but it's probably holding steady, too.
This graph shows the percent of those age 12 or older who said they used marijuana in the past month.
And yet, during those same years, marijuana has been edging toward legitimacy. States with medical marijuana laws have made it possible for thousands of people to buy pot over the counter, in actual stores. Some police departments have started de-emphasizing marijuana arrests.
Critics of liberalization believe this inevitably leads to greater consumption.
"It's axiomatic," says John Lovell, a lobbyist for California police chiefs. He's also helping to organize the campaign against an initiative in California to make marijuana legal for adults.
"Anytime you take a product — any product — from a less convenient sales forum to a more convenient sales forum, use increases," Lovell says.
But cities where marijuana have been liberalized have not seen a spike in consumption, so far. In 2003, voters in Seattle made marijuana the "lowest law enforcement priority" for city police. Researchers tracked the results. Caleb Banta-Green studies drug use trends at the University of Washington's Alcohol and Drug Abuse Institute. He says self-reported consumption and pot-related emergency room visits remained flat, before, during and after the initiative went into effect.
Banta-Green says he gets similar reports from drug researchers in other cities.
"I'm not hearing stories on a regular basis that, 'There was liberalization in marijuana policies, and soon afterwards, usage rates increased dramatically,' " he says.
At the same time, says Banta-Green, places like Seattle already had high rates of pot consumption before enforcement was relaxed, so it's not surprising that there was no big increase.
And opponents of liberalization say even if overall consumption stays flat, looser enforcement may increase pot smoking among minors.
They point to places such as California's Bay Area, where medical marijuana is commonplace and enforcement is lax. Teenagers rarely have trouble finding pot. Some get it from dispensaries; far more just buy it from a friend or classmate.