Marijuana use remains illegal in New York State, but the New York City council has voted to ban employers from testing job applicants for pot use as a condition of employment. Though the new law exempts certain employers from the ban, including transportation firms and federal contractors obligated to test for drugs, the council’s action is virtually unprecedented. Some courts in other states have ruled that workers using marijuana under medical supervision can’t be fired, but no other jurisdiction has so broadly banned preemployment testing. Advocates say that the new law will end the “stigma” associated with pot use, and they claim that testing for marijuana isn’t a good predictor of employee performance. But as with many of the arguments for legalization, these are dubious claims. The council’s action ignores substantial and growing evidence from scientific journals of pot’s negative effects, especially on younger people. And by telling employers whom they must hire, the council disregards the costs that marijuana use can inflict on a workplace.

Pot use in the workplace is nothing new. Federal contractors have been required to test for it since 1988, and testing has spread to many private-sector companies—especially those in industries where workplace accidents are dangerous and costly, including construction, manufacturing, and health care. By 2011, one survey suggested that as many as half of all employers conducted drug screening. There is compelling reason for the widespread testing. Early studies, including one 1990 report on postal workers, found that pot users were significantly more likely to cause accidents, miss work, and sustain injuries on the job than nonusers. A 2012 study published in the medical journal Addiction found that regular pot smokers displayed significantly less commitment to work than those who did not smoke.

In states that have legalized marijuana, as New York is contemplating doing, going to work high or even getting high on the job becomes more common. A recent survey of 900 pot smokers in Washington, Oregon, and Colorado found one in four admitting to getting high on the job. Another, conducted online, found that half of pot users said they had gone to work high. Random testing at workplaces has found sharply rising rates of use in Colorado, where marijuana is legal, according to Quest Diagonistics.

These kinds of results pose serious challenges for employers in states where pot is legal. The owner of one of Colorado’s largest construction companies told the Colorado Springs Gazette that since legalization, the company has had to start going out of state to find workers who can pass a test.

None of these outcomes should be surprising. A massive 2017 survey by the National Academy of Medicine outlined numerous psychological and physical problems associated with marijuana smoking, including inhibited school performance, reduced earnings potential over time, and a heightened risk of developing schizophrenia and other psychoses. The former head of the Centers of Disease Control, Thomas Frieden (who also once served as New York City’s Commissioner of Health and Mental Hygiene), described the study’s troubling findings succinctly: “Way too little known; potential benefits unproven, some serious harms definite, many serious risks possible.”

Despite these problems, the sponsor of the city’s bill, Public Advocate Jumaane Williams, described it as part of New York’s “progressive” agenda. To him, the biggest problem with marijuana is that by keeping it illegal the state is destroying the long-term employment prospects of many city residents who have been arrested for possession or failed to pass a drug test. It’s perverse logic, however. The new city law is yet another step in the direction of normalizing pot use—and that will only increase use, as we’ve seen elsewhere, with all the attendant problems that brings.

If Williams were really concerned about the long-term work prospects of city residents, he ought to heed the warnings of New Jersey State Senator Ron Rice, a former Newark cop and head of the state’s black legislative caucus, who has been leading the fight against legalization in the Garden State. Rice points out that in most places that have legalized marijuana, retail sellers have concentrated in cities with disproportionate minority populations, while upper-income, mostly white communities have typically banned pot stores. “The reality is it [legalization] will devastate the African American community,” says one of his allies in the anti-legalization crusade, Bishop Jethro James, president of the Newark–North Jersey Committee of Black Churchmen.

Mayor de Blasio says that he likes the new law, which means he’ll probably sign it. He should instead take some advice from his predecessor, Mayor Michael Bloomberg, who happens to run one of the city’s largest companies, and who recently described efforts to legalize pot in the face of rising drug use around the country as “perhaps the stupidest thing anybody has ever done.”

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