Legalizing Cannabis Doesn't Increase Marijuana Use, But Decriminalizing It Does: New Study

Calvin Hughes, James McClure

Legalizing the sale of marijuana doesn't lead to an increase in cannabis consumption, but decriminalizing the use and possession of weed does.

One common concern people have about introducing a regulated cannabis market is that allowing legal sales of marijuana will lead to more people using it. But that isn't actually true, according to new research which found that legalization doesn't cause a spike in cannabis consumption, but decriminalization does. The removal of penalties for consumption and possession of marijuana appears to have a greater impact on consumption rates than legal availability.

Researchers from Colorado Mesa University reached that conclusion after analyzing survey data generated by more than 1,400 respondents from Colorado, Washington and Australia. Those numbers showed that self-reported cannabis consumption rates spiked in each location after cannabis was decriminalized, but there was no increase in use after marijuana became available through legal retail channels in Colorado and Washington.

In Washington, cannabis use jumped by 12-22 percent among college students following decriminalization, but the state didn't see any further increase after it implemented full legalization.

In Colorado there was similarly no notable increase in cannabis consumption after the state introduced legal pot markets. And while recreational cannabis has not been legalized in Australia, the researchers reported that cannabis consumption rose by 16 percent after the country moved to decriminalize the substance.

The researchers suggest there are two primary ways to interpret their findings. They suggest that the social and legal consequences associated with illicit consumption could deter people from dabbling with cannabis, but once those ramifications are removed through decriminalization, people are more likely to try it. However, that conjecture conflicts with years of evidence showing that cannabis prohibition doesn't deter consumption.

Their second hypothesis is that cannabis consumption doesn't actually change following decriminalization. The consumption stats increase because people are more comfortable with talking about their consumption when they don't have to worry about legal or social ramifications. Basically, prohibition means people are more likely to lie about their cannabis consumption, so once it's decriminalized, survey respondents are much more willing to admit to using cannabis. 

If that's the case, then the notion that legalization or decriminalization will lead to a spike in cannabis consumption are false. People will continue to use cannabis as they did before. The only difference is that they feel less pressure to lie about it.