Hill Climbing Analogy to Drug Prohibition

Suppose we observe large numbers of people attempting to climb a tall, steep hill covered with thorn bushes. It's a mystery what they're after, but they all seem eager to reach some prize at the top. Some end up scraped up pretty badly. A few even die. But a lot of them make it up to the top without too much damage.

Someone says, "We need to put a stop to this. These idiots are hurting themselves. Let's erect a fence at the bottom of the hill!"Someone points out that this is a moronic idea. If people are willing to climb a bramble-covered hill, they'll be willing to scale your stupid fence. Maybe a few people will see the extra obstacle and that will be the final straw. The marginal hill-climbers, who were nearly indifferent to the hill climbing venture, will be nudged from a "yes" to a "no." But there is no way your silly fence will deter large numbers of people. Also, some people fall and get hurt trying to scale the fence, so this has to go into your cost-benefit calculus, too.

So you say, "Put some concertina wire at the top of the fence!" And someone points out that this is a losing game. Sure, it deters more hill-climbers. But most of this population of people, who were willing to climb a very high hill covered with thorns, are not deterred by some concertina wire. They scale the fence and snip the wire with wire-cutters. Or they throw a thick blanket over it and climb over that. Or some simply climb over the wire and take their scrapes. Some still fall and hurt themselves while scaling the fence.

Effectively, we are attempting to deter people from climbing the bramble-covered hill by placing another bramble-covered hill in front of it. This deters a few people from undertaking the venture in the first place, but the ones who venture on get twice as scraped up.

There is no way to square the circle here. To deter drug use, you must threaten some kind of harm to drug users. And to make the threat credible, you must follow through on your threat. Under pretty standard assumptions about demand elasticity, this is a losing game. Increasing the penalty (beefing up the fence, adding razor wire, electrifying it) increases the total harm to society. I think that advocates of drug prohibition have been incredibly sloppy on this point, failing to account in a serious way for total costs to society. In some vague sense, bigger penalties get you more deterrence. But we can be pretty confident that the price paid for that deterrence is too high.