An old lady walks through an estate built for refugees from the Greek-Turkish war of 1919-22 in Nikaia, southern Athens. The number of Greeks and Spaniards moving to other E.U. countries has doubled since 2007, a report said. (Petros Giannakouris/AP)

During a growing debate in the United States and internationally about the impact of immigration on government finances, a report Thursday found that the movement of people between countries has a positive economic effect.

Many countries are still struggling to recover from the global recession and suffering with high unemployment, according to the Paris-based Organization for Economic Cooperation and Development, which represents the world’s richest nations. That has led people to unfairly target immigrants as a drain on a country’s resources, the group said in its annual report on migration released Thursday.

The OECD found that the fiscal effect of immigration is small, generally not pushing a country’s gross domestic product more than 0.5 percent in either direction. According to the report, immigration was a net contributor to the U.S. economy in 2011 and increased GDP by 0.03 percentage points.

The calculation compares immigrants’ tax and Social Security contributions to the resources they use, including social and government services. This type of analysis, however, excludes the migrants’ longer-term impact on the economy.

Congress has been considering legislation to overhaul the United States’ immigration system.

International migration picked up only slightly — 2 percent — in 2011, but much of the growth was driven by movement within the European Union, where sweeping unemployment in some countries prompted workers to seek employment elsewhere within the union.

While migration rose 2 percent in the United States in 2011, it leapt 15 percent in Europe, the report found.

This has largely been driven by people leaving the countries hardest hit by the economic slowdown. The number of people emigrating from Greece and Spain, two countries still in the midst of a recession, has doubled since 2007.

Between 2011 and 2012, Germany had a 73 percent increase in Greek immigrants, close to a 50 percent rise in Spanish and Portuguese immigrants and a 35 percent increase in Italian immigrants.

The OECD found that immigrants still face discrimination in many countries. A person with a foreign-sounding name, for example, had to send at least twice as many applications to get a job interview than one with a non-foreign name.

“Governments must do everything they can to improve immigrants’ job prospects,” Angel Gurria, the OECD’s secretary general said in a statement. “Continuing to help immigrants integrate will also ensure they can play their part in driving growth as the global economy recovers.”