Over the past two years, the Trump administration has continually used the economic weight of the US economy migrants as justification for his policy "zero tolerance" on the borders.

Trump has personally called the migrants "animals" who want to "infect" the United States.
It repeatedly and falsely referred violent impact of immigration in Europe to justify the hard line of his administration.
Monday, Trump wrote the "big mistake made by Europe in letting millions of people who have violently changed their culture!"
According to new research published today in Science Advances, however, asylum seekers in Europe have brought benefits to the economies of host countries.
The research was conducted by the French National Center for Scientific Research, University Clermont-Auvergne and Paris-Nanterre, and uses economic data from 15 different cities in Western Europe with the highest influx of asylum seekers from 1985 and 2015.
During the nineties, Western Europe has seen a large influx of asylum seekers following the Balkan war.
Over the past seven years, as we know, there was another increase in landings from the Mediterranean.
In addition, the researchers note, the flow of migrants has grown from the extension to the east of the European Union in 2004.
To see the impact of asylum seekers and migrants on economic indicators such as GDP per capita, unemployment and public finances, the researchers used a statistical model developed by Nobel laureate Christopher Sims economy.
This pattern gave the researchers a better picture of how asylum seekers influence on national economies in comparison to other models, which consider the economic impact of migrants as an equation input-output (how much governments spend against how much they pay for them their taxes), but do not account for other economic interactions predicted by the model Sims.
In addition, they found that "public spending on the economic burden of refugees made much larger gain in the form of taxes."
According to the researchers, the economic effects of asylum seekers who are coming up now will be perceived from three to seven years, when some of them are real residents.
"We do not deny that a large proportion of asylum seekers has led to challenges both in terms of internal and external policy.
However, these political challenges could easily be lightened if you let go of the idea that migrants are an economic burden. "

From Vice