A study from the University of Basel has concluded that while immigration may have short-term economic benefits for Western nations, in the long term it could heavily strain a country’s welfare system.

The study examined the long-term effect of mass migration and concluded that while new migrant households in Switzerland pay around 729 francs per household per month more in taxes than they receive in benefits, that number becomes a 405 francs loss in the long term, Kronen Zeitung reports.

The driving factor behind the long-term loss is that migrants, like native Swiss, age and often pay less overall in taxes before retirement. Another factor is higher unemployment rates among migrants, which is twice as high as native Swiss or foreign EU nationals and four times as high for migrants from outside of the European political bloc.

Just over 70 percent of unemployment insurance money comes from native Swiss taxpayers, but they only take out 55 percent of the total unemployment benefits.

Study: Migrants Hurt Long Term Economic Growth https://t.co/YzW2mvu0J4 pic.twitter.com/TNSN6sXz0F — Breitbart London (@BreitbartLondon) June 18, 2016

In some countries, the unemployment rate is even higher for migrants and those from migrant backgrounds. Recently released figures from Sweden showed that while native Swedes had a very low unemployment rate of 3.6 percent, migrants and residents from migrant backgrounds had a rate of 19.9 percent.

One of Germany’s top economists Hans-Werner Sinn has also warned Germany and other countries that many low-skilled migrants are attracted by generous welfare state programmes, as opposed to the high-skilled workers often demanded by governments.

In 2015, Mr Sinn and the Ifo Institute recommended the German government raise the retirement age in order to help pay for the migrants flooding into the country at the height of the migrant crisis.

Such a policy was announced by Sweden in December of last year when Swedish Socialist party Finance Minister Magdalena Andersson said the retirement age would likely have to be raised to pay for new migrants.

Municipalities across the country may also have to raise taxes to pay for new migrants, according to a report from the Swedish National Institute of Economic Research from March of this year.