Possessing up to an ounce of marijuana in California is an "infraction" punishable by a $100 fine. In other words, state law treats pot smoking as a transgression akin to jaywalking or fishing without a license. Yet growing and selling marijuana are felonies that can send you to prison for years.

If consuming marijuana is not a crime, how can it be a crime merely to help someone consume marijuana? That is a question voters will confront next fall if the California Cannabis Hemp Initiative qualifies for the ballot.

The initiative, which would eliminate all state and local penalties for producing, possessing, and distributing marijuana, instructs the legislature to regulate cannabis "in a manner analogous to, and no more onerous than, California's beer and wine model." That is similar to the policies approved last fall by voters in Colorado, where the legalization initiative was known as the Regulate Marijuana Like Alcohol Act, and Washington, where the state liquor control board will license pot shops that are scheduled to open next year.

The Colorado and Washington initiatives both received about 55 percent of the vote, and recent polling in California indicates a similar level of support. All three states have had medical marijuana dispensaries for years, and that experience on the whole appears to have been reassuring.

The main criticism of the dispensaries—that they cater largely to recreational consumers who fake or exaggerate symptoms to get the requisite doctor's notes—actually counts in favor of broader legalization. If medical marijuana is a charade that amounts to de facto legalization, what is there to fear from making it official?

States that allow medical use do not seem to have suffered as a result. In fact, Montana State University economist D. Mark Anderson and University of Colorado economist Daniel Rees find that enacting medical marijuana laws is associated with a 13 percent drop in traffic fatalities, possibly because more cannabis consumption means less alcohol consumption, which has a much more dramatic effect on driving ability.

Anderson and Rees also consider the impact of legalization on pot smoking by teenagers. Looking at data from the Youth Risk Behavior Survey from 1993 through 2011, they see "little evidence of a relationship between legalizing medical marijuana and the use of marijuana among high school students." Narrowing the focus to California after medical marijuana dispensaries began proliferating, they find "little evidence that marijuana use among Los Angeles high school students increased in the mid-2000s."

The two economists' conclusion suggests that Californians need not worry that repealing pot prohibition will trigger a cannabis catastrophe: "We expect that the legalization of recreational marijuana in Colorado and Washington will lead to increased marijuana consumption coupled with decreased alcohol consumption. As a consequence, these states will experience a reduction in the social harms resulting from alcohol use. While it is more than likely that marijuana produced by state-sanctioned growers will end up in the hands of minors, we predict that overall youth consumption will remain stable. On net, we predict the public-health benefits of legalization to be positive."

That prediction hinges on the assumption that marijuana and alcohol are substitutes, meaning that an increase in pot smoking will accompanied by a decrease in drinking. Writing in the same issue of the Journal of Policy Analysis and Management, RAND Corporation drug policy expert Rosalie Liccardo Pacula and University of South Carolina criminologist Eric Sevigny say the evidence on that point "remains mixed." If marijuana and alcohol turn out to be complements, they warn, the costs associated with more drinking could outweigh the benefits of legalization.

Yet Pacula and Sevigny acknowledge that the hazards associated with marijuana itself pale beside the cost of treating its production, sale, and use as crimes. Which brings us back to the question of how using force to stop people from obtaining marijuana can be morally justified, especially in a society that tolerates a much more dangerous intoxicant.

This article originally appeared in The Orange County Register.