WASHINGTON -- Mark Kleiman, the Washington state “pot czar” and a leading drug policy expert who has criticized a state-by-state approach to marijuana legalization, came out on Thursday in favor of Oregon’s ballot measure to legalize the drug for recreational purposes.

In a blog post, Kleiman wrote that he supported the measure, despite concerns that legalization would lead to lower prices and higher usage.

“The choice Oregon voters face isn’t between what’s on the ballot and some perfectly designed cannabis policy,” Kleiman wrote. “It’s between what’s on the ballot and continued prohibition at the state level, until and unless a better initiative can be crafted, put before the voters, and passed into law.”

Even though he supports the measure, Kleiman wrote that the state legislature should raise taxes on the drug to prevent minors and frequent users from easily accessing it. Under the proposed regulations, Oregon would only impose a $35-per-ounce sales tax on the final purchase of the drug, which Kleiman argued would only add a trivial 50 cents to the price of a legal joint.

“Unless the legislature decided to raise it, the $35-per-ounce tax in Measure 91 would lead, within a couple of years, to prices way below current illicit prices and way below legal prices in Washington State,” Kleiman wrote. “That in turn would mean big increases in use by minors and in the number of Oregonians with diagnosable cannabis problems. It would also mean substantial diversion of cannabis products legally sold under Oregon’s low taxes to Washington, where taxes are much higher.”

In focusing so strongly on weakening the black market for marijuana, the Oregon measure neglects to address many of the consequences of creating a legal market for marijuana, Kleiman argued.

“Focusing on the goal of eradicating the illicit cannabis market in Oregon, it doesn’t pay enough attention to the risk that Oregon might become a source of illicit supply to neighboring states,” Kleiman wrote. “Focusing exclusively on preventing use by minors, it neglects the risk of increasing dependency among adults.”

Despite his concerns about the law, Kleiman said that legislators are more likely to act to remedy problems after the law is passed, rather than tackle the issue on their own.