Pesky Evidence

I’ll admit to being one of the multitude of fans who have made shows like NCIS and CSI such hits. It isn’t that I don’t recognize how unrealistic they are—no publicly financed lab could afford such cutting-edge equipment even if someone invented it—but I love watching the search for hard evidence, and the characters’ willingness to abide by what that evidence shows even when the result is to exonerate some really unattractive suspect.

Wouldn’t it be nice if those we elect to make policy were similarly devoted to evidence-based decision-making?

In the real world, unlike the televised version, policymakers routinely disregard research that doesn’t match their ideological preferences. I’m not talking about a couple of studies where the results are ambiguous, or subject to conflicting interpretation. I’m talking about policies where the evidence is copious and expert consensus compelling. Global climate change is one such area; our incredibly expensive “drug war” is another.

Some years ago, I got a call from a teacher in northern Indiana who wanted to arrange a public forum on the pros and cons of our punitive drug policies. In private conversations, the Chief of Police, a local judge and the prosecutor had all told him that prohibition simply doesn’t work. Not one of them, however, would repeat those sentiments in public. My students who are police officers consistently tell me that alcohol—which is regulated but legal—is a much greater problem than marijuana, because people are more aggressive when they are boozed up than when they are zoned out.

The fiscal consequences of our current policies are staggering. In 2005, an economics professor at Harvard reported that replacing marijuana prohibition with a system of taxation and regulation similar to that used for alcohol would produce combined savings and tax revenues between $10 and $14 billion per year. Estimates from a variety of sources are that marijuana prohibition costs U.S. taxpayers nearly $42 billion dollars a year in criminal justice costs and lost tax revenues. This is just from marijuana prohibition—not efforts to control harder drugs.

Estimates are that the money spent annually on the drug war would pay for a million additional teachers.

Then there are the opportunity costs. Indiana used to have a robust hemp industry. Hemp is an enormously versatile and useful product that cannot be smoked or used as a recreational drug, but our indiscriminate policies outlaw its growth. They also prohibit use of marijuana to alleviate the side effects of chemotherapy.

Other states have begun to rethink these policies. Fifteen states have legalized medical marijuana. Oakland, California has begun assessing a sales tax on marijuana sold in marijuana dispensaries.

I recently had a call from a group hoping to convince the Indiana legislature to revisit policies on medical marijuana. The caller asked what the evidence showed.

I told him that the evidence conclusively demonstrated two things: that the drug war is both costly and counterproductive, and that in politics—unlike television—evidence is irrelevant and ideology rules.