The Bush administration's top economic advisors say immigration benefits native-born workers in the United States.
A report issued Tuesday, by the President's Council of Economic Advisors also says immigrants make up more than 15 percent of the U.S. workforce, and they pay more in taxes than they use in benefits.
Immigrants are concentrated in the lowest and highest economic levels - those without a high school diploma, and those who hold a doctorate degree.
Fierce political debates have been going on in the United States over how to cope with the estimated 12 million people who have already migrated here illegally. Congress and the Bush administration are also haggling over who should be allowed to immigrate in the future.