You don't need to worry about this as much as you used to. (AP Photo/Alex Brandon)

On Monday, we ran a story about how despite the fact that smoking marijuana is now essentially legal in Washington, D.C., employers are planning to keep making workers pee in a cup — both before someone is hired and intermittently on the job. In Colorado, which has also legalized pot, drug testing has actually ticked up a bit, with companies worried that the state’s burgeoning pot industry might start to infiltrate the workplace.

But that hides the longer-term trend: Employers drug test a lot less than they used to because there’s very little evidence that testing does much to improve safety or productivity.

Workplace drug testing started taking off after President Ronald Reagan required it for federal employees in 1986, and it peaked during the drug war of the 1990s. When the American Management Association first started polling employers on whether they subjected their employees to drug tests, in 1987, 21 percent said they did. By 1996, the number was up to 81 percent. But that percentage steadily declined through 2004, the last time the AMA asked employers about drug testing, when the number was down to 62 percent.

[D.C. employers find themselves on front line of new marijuana policies]

Lewis Maltby, president of the National Workrights Institute, produced a report while at the American Civil Liberties Union in the 1990s arguing that drug testing was ineffective — the National Academy of Sciences had just come out with a study showing that moderate use of marijuana off duty was no more predictive of poor performance than use of alcohol.

"In the long run, the drug testing advocates mostly lost, and not because of us,” Maltby says. "All the ACLU did was tell employers what they were already learning on their own, which is that drug testing is a waste of money.”

Some studies over the years have shown that increased drug testing has been accompanied by a decrease in illicit drug use, but many of them come from the drug testing industry itself. (Quest Diagnostics, which performed 8.4 million tests last year, found that positivity rates actually increased in 2014, for the first time since 2003.) Another study, from the journal Health Services Research in 2007, found that companies with drug testing policies often also had other deterrence programs -- like anti-drug policies and educational materials -- which also may have been responsible for the decline. Some, like a study showing that drug testing helped cut down on drug use within the military, aren’t perfectly analogous to all workplaces.

The federal government is still the nation’s biggest drug tester, subjecting 400,000 employees in mostly transportation and national security-related positions to testing. In contrast to policy documents from the last White House, however, President Obama’s 2014 National Drug Control Strategy mentions drug testing only in the context of reducing drugged driving, treating addiction and monitoring convicted drug offenders.

It’s possible that we’ll never see the prevalence of drug testing decline to pre-1980s levels — it’s much harder to scrap a testing policy than to institute one.

"I think employers look at preemployment drug testing as 'Eh, it couldn’t hurt,'" says Maltby. "It’s become sort of a game. Employers know that it doesn’t mean anything. Anyone who smokes pot will just stop for a few days. It’s an empty ritual that nobody wants to be the first to give up."

At the moment, drug use isn’t the barrier to employment that criminal records can be. Barbra Kavanaugh, executive director of the Employment Justice Center in Washington, runs an employment clinic that helps underprivileged people deal with issues like wage theft and workers compensation claims. Occasional drug testing, she says, hasn’t turned up as much of a problem. (In fact, one study suggested that employment prospects for black people actually improved in businesses that drug test.)

Still, Kavanaugh says, she’d rather drug testing not exist at all.

“Anything that removes arbitrary or unrelated barriers to employment is a good thing,” she says.

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