Updated March 8, 2012, 11:16 a.m. ET.

U.S. Top Destination for Christian, Buddhist Immigrants, Study Says .

By TAMARA AUDI

The U.S. is the top destination for the world's migrating Christians and Buddhists, as well as those with no particular religious affiliation, including atheists and agnostics, a new study showed.

The pattern is among the revelations in a map of religious migration across the globe released on Thursday by the Pew Research Center.

The map also shows that Europe has more Christian immigrants than Muslim immigrants. Millions of Muslims are on the move, mostly to other Muslim countries.

The study examined the religious identities of people living a year or longer in a country other than the one in which they were born as of 2010. It used world-wide census and United Nations data to determine the results.

While religious persecution and escape from violent conflict can be factors in migration, the single-largest driver is economic opportunity, immigration experts say. Still, people bring their faith with them when they move, said Phillip Connor, a Pew researcher and lead researcher of the study.

"Immigration changes societies. It changes the religious landscape," Mr. Connor said. He noted that at one time the U.S. was mostly Protestant but that today it is only about half Protestant.

Christians, 33% of the world's population, make up nearly half of the world's 214 million living migrants, the study shows. Christian migration is largely driven by migration from Latin America to the U.S. Of the 43 million foreign-born people living in the U.S., nearly three quarters are Christian.

Russia, with 12 million immigrants, is the second-most-popular destination for immigrants, followed by Germany, with more than 10 million immigrants. Saudi Arabia and Canada were next, each attracting just over 7 million immigrants.

Mexico is the largest country of origin of Christian migrants, most of them now living in the U.S., the report says. The U.S. has received more than 12 million mostly Christian immigrants from Mexico alone, it says.

Despite the concerns of some in Europe over a rise in Muslim immigration, the study says that Christian immigrants outnumber Muslim immigrants in the 27 countries of the European Union. Around 26 million Christian immigrants make up 56% of the immigrant population of the EU nations; Muslim immigrants make up 27%, with 13 million foreign-born Muslims living in the EU. When migration from one EU country to another is excluded, the percentages are closer, but Christian immigrants still outnumber Muslim immigrants 13 million to 12 million, the study says.

Muslims are the second-largest group of international migrants, making up 60 million, or 27%, of the world's migrants. Many of them have migrated from India, Pakistan, Indonesia and the Philippines to Saudi Arabia. The Palestinian territories are the largest single source of Muslim migrants, with 5.7 million Palestinians exiting the region for other countries.

The massive migration of foreign-born workers to Persian Gulf countries has also injected some religious diversity into overwhelmingly Muslim countries, according to the report. There are more than 2 million Christian immigrants in six Gulf countries, as well as 1.4 million Hindu immigrants and half a million Buddhist immigrants.

Population projections show Gulf countries are expected to remain majority Muslim, but "if the pace of immigration to the region continues, some [Gulf] states…may see dramatic changes in the religious composition of their societies," the Pew report says.

Hindus tend to stay put, making up only 5% of the world's migrants but 10% to 15% of the global population. When they do move, they go to India, followed by the U.S.

No religious group has a higher level of migration than Jews, the study found. Although Jews make up only a sliver of the world population—less than 1%—and just 2% of the migrant population, a quarter of all living Jews today have left the country of their birth to live somewhere else. By contrast, just 5% of living Christians and 4% of Muslims have migrated to other countries, the study says.

Most of the 3.6 million Jewish migrants left Europe, and the overwhelming majority of those—3 million—ended up in Israel, according to the report.

Write to Tamara Audi at tammy.audi@wsj.com

U.S. Top Destination for Christian, Buddhist Immigrants, Study Says - WSJ.com