SINCE the early 1990s, when the principle of free movement was expanded by a series of European Union directives and court rulings, more European citizens have arrived on British shores each year than have left. But Brexit threatens to reverse this pattern. In the 12 months to June 2017, net migration (immigration minus emigration) from the EU fell to around 100,000, its lowest level in four years (see chart). Among the eight central and eastern European countries that joined the union in 2004, of which Poland is the biggest, net arrivals are heading towards zero. This trend has led many to wonder what Britain will be like if it becomes an exporter of European migrants, rather than an importer.

One way to glimpse that future is to consider Harrogate, a spa town in the north of England which is a few years ahead of the trend. The town is home to roughly 75,000 people, with the same number living in the rest of the local authority area. Its good schools, pretty Victorian terraced houses and proximity to the Yorkshire Dales mean that it frequently tops lists of the best places to live. Small wonder, then, that it welcomed throngs of newcomers, many of them Polish, in 2004. Arrivals of Europeans jumped from about 200 to 800 per year. Nowadays a tenth of its population is foreign-born.

But the inflow of migrants has slowed and many have started to leave. Every year since 2012 more foreigners have left Harrogate than have arrived, according to official figures. These estimates are far from perfect, but the town already exhibits the characteristics of a place lacking migrants—and shows what other parts of Britain can expect if the national trend continues.

One is a tighter labour market. On the high street, dozens of shops display help-wanted notices. Care homes, of which the town has several, have seen a jump in vacancies. Waiters are in high demand. Costas, a Greek barman, has had three jobs in the past few months. When a branch of the Ivy, a fancy restaurant, opened in November it sucked in roughly 100 staff from local eateries, says the manager of a pizza joint. Unemployment has fallen to 3.6%, below the national and regional levels, allowing some workers to drive harder bargains. Though real median wages in Harrogate have not changed much since 2014, at the lower end they have risen by 9%.

Two factors heighten the labour shortage. First, the town’s big industries, which include retail, hospitality and social care, are ones that typically rely on migrants. Second, there is a dearth of young people. Many go to university at the age of 18 and return to start a family at 35. And Harrogate lacks a university or big college of its own, so casual student workers are thin on the ground. All this means that emigration is harder felt.

No statistics on local migration since the Brexit referendum in 2016 have been published, but many in Harrogate suspect that the pace of departures has increased. The number of online ads for hospitality jobs in the local area rose from 771 in 2016 to 1,119 in 2017, according to data from Labour Insight, a research firm. Joanna Slusarczyk, who runs a Polish grocery, says some migrants felt unwelcome after the referendum (in which Harrogate voted narrowly to remain). Teachers report that some British children began teasing eastern Europeans about Brexit in the playground.

The outflow is also felt in the housing market, says Simon Croft of Feather, Smailes and Scales, a local estate agent. Demand for low-end rented properties has fallen. In Harrogate, prices in this segment grew at half the regional average between 2014 and 2017. Many Poles seem to be seeking work elsewhere in the EU rather than going home. Their forwarding addresses tend not to be in Poland, but in Germany or France, says Mr Croft.

Some businesses are adapting to the stretched labour market. Simon Cotton, the head of HRH Group, a chain of hotels, is renovating one of his Harrogate properties. Attaching furniture such as bedside tables and toilets to the wall, rather than resting it on the floor, makes cleaning underneath quicker, and might make it possible to employ one cleaner fewer. Automation also helps. Investing in an industrial dishwasher could eliminate the need for a kitchen porter, he says.

Another strategy is to lure younger and older workers into the labour market. Some businesses in Harrogate are paying teenagers well above their minimum wage of £4.05 ($5.70) per hour, to tempt them into work. Matthew Roberts, an economic-development officer at Harrogate Borough Council, says that as the population continues to age, employers will have to rely on older people to fill jobs.

Locals worry about who will care for the elderly and wait on tables in restaurants if migrants continue to leave. Moia Wood, a primary-school teacher who specialises in working with minority groups, says many people in Harrogate don’t realise how much migrants do for them. They are beginning to find out—and soon the rest of Britain will, too.