In 2012, Colorado and Washington state became the first states to vote to legalize marijuana for recreational purposes. Since then, nine more states and Washington, DC, have followed — although Vermont and DC, while allowing marijuana possession and growing, have continued to bar sales for recreational purposes.

The spread of marijuana legalization has led to a reimagining of US drug policy and how, exactly, it should change as people seek alternatives to punitive criminal justice policies that have led to more incarceration and a black market that supports violent criminal enterprises.

But marijuana remains illegal under federal law. And although the Obama administration said it would allow state-level rules to stand without much federal interference, the Trump administration has taken a tougher line.

With the exception of Vermont, the states that have legalized marijuana for recreational purposes so far have landed on a commercialization model, where for-profit, private businesses sell the drug. State officials also enforce some limits on sales, including an age requirement (21 and older), how much a person can buy and possess at once, the packaging of the product, and taxes.

But drug policy experts point out that commercialization isn’t the only way to legalize the drug. In a January 2015 report for the Vermont legislature, some of the nation’s top drug policy experts outlined several alternatives, including allowing possession and growing but not sales (like DC at the time), allowing distribution only within small private clubs, or having the state government operate the supply chain and sell pot.

The report particularly favors a state-run monopoly for marijuana production and sales to help eliminate the black market and produce the best public health outcomes, since regulators could directly control prices and who buys pot. Previous research found that states that maintained a government-operated monopoly for alcohol kept prices higher, reduced youth access, and reduced overall levels of use — all benefits to public health.

The different alternatives show that even for people who support legalization, there are some choices to be made. It isn’t just about choosing between legalization and prohibition; it’s also about choosing which form of legalization would produce the most benefits — by reducing incarceration and weakening the violent black market for pot — and minimize the negative outcomes of potentially increased drug use.