HOW modern and liberated Germany’s Social Democrats and Greens sounded in 2001. They were in government and wanted to raise the legal and social status of prostitutes. So they enacted a law to remove the stigma from sex work by, for example, giving prostitutes full rights to health insurance, pensions and other benefits. “Exploiting” sex workers remained criminal, but merely employing them or providing them with a venue became legal. The idea was that responsible employers running safe and clean brothels would drive pimps out of the market.

Germany thus embarked on an experiment in liberalisation just as Sweden, a country culturally similar in many ways, was going in the opposite direction. In 1999 the Swedes had made it criminal to pay for sex (pimping was already a crime). By stigmatising not the prostitutes but the men who paid them, even putting them in jail, the Swedes hoped to come close to eliminating prostitution.

The two countries’ divergent paths have become hot political fodder in Germany. The centre-right camp led by Angela Merkel, the chancellor, voted against the 2001 prostitution law. In September it won the election but fell short of a majority in parliament. Mrs Merkel is now negotiating with the Social Democrats (SPD), the co-authors of the law, to form a coalition. And although the SPD is reluctant to acknowledge that it made an outright mistake, it is conceding that changes are needed.

Prostitution seems to have declined in Sweden (unless it has merely gone deep underground), whereas Germany has turned into a giant brothel and even a destination for European sex tourism. The best guess is that Germany has about 400,000 prostitutes catering to 1m men a day. Mocking the spirit of the 2001 law, exactly 44 of them, including four men, have registered for welfare benefits.

The details vary regionally, because the federal states and municipalities decide where and how brothels may operate. (Berlin is the only city without zoning restrictions.) In some places, streetwalkers line up along motorways with open-air booths nearby for quickies. In others, such as Saarbrücken, near the border with a stricter country like France, entrepreneurs are investing in mega-brothels that cater to cross-border demand.

If all these sex workers were in the business of their own free will, that would still be within the spirit of the 2001 law. Prostitutes’ associations insist that this is largely the case. But nobody denies that many women become sex workers involuntarily. Of particular concern are girls from poor villages in Romania and Bulgaria who may have been forced, tricked or seduced to come to Germany. Once there, they are trapped as Frischfleisch (fresh meat) in brothels, perhaps because they owe money to their traffickers or fear reprisals against their families at home.

Extreme opponents of prostitution in Germany, such as Alice Schwarzer, a radical feminist, conflate modern slavery and sex work, arguing that they are “inextricably entangled”. (Ms Schwarzer has issued a petition, signed by celebrities, to criminalise paying for sex as Sweden has.) Barbara Kavemann and Elfriede Steffan, two social researchers, say that slavery and sex work are in fact separate phenomena, and that occurrences of forced labour by Romanians and Bulgarians in the trade, as in agriculture and other sectors, “have little to do with the prostitution law” and much more with the accession of those countries to the European Union in 2007.

Known cases of human trafficking have actually decreased in Germany, from 987 in 2001 to 482 in 2011. Sceptics counter that most cases never become known because the girls are afraid to testify. The link between liberalisation of prostitution and human trafficking thus remains controversial. One study of 150 countries found that legalisation expands the market for sex work and thus increases human trafficking. Prostitutes’ associations have attacked the study as poorly sourced.

In the end, the policy choice comes back to culture and ideology, argues Susanne Dodillet at the University of Göteborg. Both the Swedish and the German laws originated in the feminist and left-leaning movements in these countries. But whereas progressive Swedes view their state as able to set positive goals, Germans (the Greens, especially) mistrust the state on questions of personal morality as a hypocritical and authoritarian threat to self-expression. Only this can explain why Swedes continue overwhelmingly to support their policy, and Germans theirs.