Like almost everyone who lauds Swedish prostitution policy, Globe and Mail columnist Margaret Wente ignores an obvious and critical factor in judging the effects of that policy: geographic displacement.

”œAcross the bridge from southern Sweden is Denmark,” Wente writes. Denmark took a more liberal approach than Sweden and in sharp contrast to its neighbour it is now awash in prostitution. Ergo, the Swedish policy of criminalizing customers works. Legalization doesn’t.

I question whether the contrast is really so stark as Ms. Wente makes it out to be. I know from long experience researching this issue that the data cited in prostitution debates ”” particularly that delivered by ideologically driven prohibitionists ”” ranges from the sketchy to the fabricated. But for present purposes I’ll simply assume the reality is exactly as Ms. Wente portrays it. And as portrayed, it sounds convincing. Sweden took one path, it’s neighbour another: It’s a natural experiment and the results are clear.

But remember that bridge Ms. Wente mentioned? It connects the Swedish city of Malmo with the Danish capital of Copenhagen. Of course there are no border controls. To travel from Malmo to Copenhagen you simply hop on a little train that zips over the cold Baltic waters. It takes 35 minutes city to city and costs 9 Euros.

Stockholm lies far away to the north-east. The train-ride to Copenhagen takes 5 hours ”” the same time it takes a train to travel from Ottawa to Toronto.

But Copenhagen isn’t the epicentre of legal prostitution in Europe. Amsterdam is. A flight from Stockholm to Amsterdam takes two hours.

So what would we expect to happen if Sweden criminalizes the customers of prostitutes while Sweden’s neighbours legalize and regulate prostitution? Swedish customers will go elsewhere.

And they do. In large numbers. In Amsterdam researching Dutch social policy, I once asked a Dutch prostitute what she thought of the Swedish policy. She was all for it, she said. It’s good for business.

For Ms. Wente and others of like mind, the goal of prostitution policy is not simply to push prostitution from one neighbourhood or city to another. Law enforcement has always been able to do that quite easily. No, the goal is to diminish prostitution to the greatest extent possible. To the extent that Sweden’s punitive policy simply displaces prostitution to its neighbours, it is failing. Of course, Swedes who loathe prostitution may be thrilled ”” just as residents of a neighbourhood are happy when the cops conduct a sweep that drives prostitution into some other neighbourhood. But it hasn’t actually accomplished what it is intended to do.

It’s a glaring problem. But rather than discuss it, advocates of the Swedish policy simply pretend it doesn’t exist.