BELGIANS must believe Siemiatycze is the capital of Poland, residents of this eastern Polish town like to quip. Those that are left, that is. Since before the fall of Communism Brussels has been the destination of choice for thousands of Siemiatyczans who seek work abroad. Accurate figures as to just how many have left are hard to come by, as people often retain Siematycze as their official place of residence. But it is clear that the real population of the town, at any given moment, is considerably less than the official figure of 15,000.

Poland’s Central Statistics Office estimates that 2.1m Poles are living abroad, most within Europe. That figure peaked at 2.3m in 2007, after which some people started to move back. Yet predictions of a mass return of emigrants as Western Europe slid into recession (whereas Poland did not) proved wrong. For the past three years, the number of emigrants has been rising steadily again. Alarm bells are ringing in Warsaw.

The largest number of expatriate Poles are in Britain, followed by Germany and Ireland. But there are sizeable contingents all over Western Europe and Scandinavia. Family and neighbourly connections mean that some towns develop relationships with particular destinations abroad, as is the case between Siemiatycze and Brussels.

Every Friday morning three coaches leave Siemiatycze for the Belgian capital. The driver of the state-run PKS service jokes bitterly that the biggest change capitalism has brought to the town is competition for passengers from two private companies. On board, those settling in for the 20-hour journey are all going either to visit relations working in Belgium, or to look for jobs themselves. All tell the same story: there is no work in Siemiatycze. Magdalena, aged 26, is considering joining her mother, who left 16 years ago and is working in Brussels, “as a cleaning lady, of course”.

Unemployment in Siemiatycze stands at 10.5%. That is lower than both the national average of 13% and the 14.6% average for the Podlasie Voivodship, where the town is situated. But to a large extent that is because people prefer to leave to than sign on as jobseekers in a town where positions paying more than the minimum wage of 1,600 złoty ($510) are rare.

Remittances have visibly benefited the local economy, however. “It’s only thanks to the emigrants that we still have jobs here,” says Alicja from behind the counter of a café by the bus station. Handsome new houses are seen all over town. Shops do a roaring trade during holidays, when crowds come back from Belgium to spend their euros on cheaper Polish products.

Yet Siemiatycze's residents are painfully aware that this is neither an economically nor socially healthy state of affairs. Some teenagers left behind turn to alcohol and drugs; older people are distressed to see their grandchildren born abroad. Like countless other Polish towns, Siemiatycze is slowly emptying out. Emigration is exacerbating a demographic crisis that sees hundreds of schools across the country closed every year.

Siemiatycze is an extreme example of a pattern that has been seen across Poland for many years: low-skilled workers from rural areas and small towns leave for low-skilled, but better paid, work abroad. From bigger cities, graduates and skilled technical workers are also emigrating, usually with a plan to save up for a few years and then return. The statistics suggest that it does not always work out that way.

Even so, Paweł Kaczmarczyk of Warsaw University’s Centre for Migration Research believes that in the future more and more of those migrants will move back to Poland. Economic uncertainty, he says, discourages them from moving back, but that should abate. The wage gap between Poland and Western Europe is steadily narrowing.

Mr Kaczmarczyk prefers to stress the positive aspects of the exodus. Some 90% of Polish emigrants have found work in their adoptive countries, he notes, albeit often below their level of qualification. Poles’ willingness to move around in search of better pay has shown, he argues, that a European labour market can exist. Such mobility, and attendant language skills, will be ever more valued in the future.

Employers value the skills and practices workers acquire abroad, but in many areas they are still faced with a stubborn problem: the salaries they offer cannot compete with those offered by employers in Germany and beyond. Anna Kwiatkiewicz of the Lewiatan employers’ confederation complains of a “skills drain” among technical workers. She says that if Polish workers can’t be lured back, the government urgently needs a pro-active policy to encourage immigration to replace them.

Poles increasingly bemoan the lack of a coherent government policy on migration in either direction. They are inclined to view the continuing exodus as a sign that their government is failing them—and less inclined to share the optimism of people like Mr Kaczmarczyk. For Poland’s politicians, smiling benignly on a phenomenon that brings the unemployment figures down will no longer do.