As France's anti-immigration National Front stands on the edge of historic gains in the first round of regional elections, it is time to debunk the theory that high rates of immigration improve economic growth.

Over the past decade, Europe has seen a massive influx of immigrants.  According to the U.N., the total international migrant stock in Europe increased by almost 30 percent, from 56 to 72 million immigrants, between 2000 and 2013.  With the European Union's stagnant population dynamics, this translated into an even higher increase in the EU's international migrant stock as a percentage of its population.

Back in the 1960s, a little over 3.5 percent of the EU's population was made up of immigrants.  Currently, the value is over 10 percent and climbing fast with 2015's refugee invasion.  If we accept the mainstream economic theory that increased immigration improves economic growth rates, Europe's economy should be forging ahead at an all-time record.

Nothing could be farther from the truth. Some sobering statistics to contemplate:

• In France, home of the National Party, real per capita GDP peaked in 2007 at $37,639.  Since then, it has declined by more than 1.1 percent, with a decline last year by 0.2 percent.
• In the Netherlands, home of the Party for Freedom, real per capita GDP peaked in 2008 at $47,388.  Since then, it has declined by 4.4 percent.  The 2013-2014 growth rate was anemic at just 0.6 percent.
• In Denmark, home of the Danish People's Party, real per capita GDP peaked in 2007 at $45,609.  Since then, it has declined by 6.2 percent.  The country saw a growth rate of only 0.7 percent from 2013 to 2014.
• In Belgium, home of the New Flemish Alliance, real per capita GDP peaked in 2008 at $41,641.  Since then, it has declined by 1.8 percent, and, as with Denmark, last year's growth rate was just 0.7 percent.
• In Austria, home of the Freedom Party of Austria, real per capita GDP peaked in 2012 at $44,216.  Since then, it has declined by 0.7 percent, and in 2013-2014 the per capita GDP further contracted by 0.3 percent.
• In Hungary, home of Jobbik, the current real per capita GDP of $23,609 is only 1.2 percent higher than it was back in 2008.
• In the United Kingdom, home of UKIP, real per capita GDP peaked in 2007 at $38,164.  Since then, it has declined by 1.4 percent.

In other countries, the situation is even worse.  Real per capita GDP has declined 12 percent in Italy since the 2007 peak, and a further 2.2 percent decline took place last year.  Greece's real per capita GDP is now 24 percent lower than it was in 2007.  Portugal's is more than 6 percent lower than it was in 2008.  In Spain, the decline is 7.4 percent.

For the EU as a whole, real per capita GDP peaked in 2008 at $35,012.  Since then, it has declined by a full percentage point.

Most of Europe is living through a decade-long period of economic decline and massive debt increases.  And yet, over this period, immigration has been at record high levels.

The data for Europe since the mid-2000s puts a nail in the coffin of multinational corporatist theories that high rates of immigration result in improved economic conditions.  The rise of Europe's nationalist parties is not only understandable; it is desirable.  Only by throwing out failed open borders theories of macroeconomics will Europe be able to regain its footing, both socioeconomically and politically.