Black people who immigrate to the United States from the Caribbean and sub-Saharan Africa tend to earn more money and have a slightly higher level of education than native-born black Americans, according to a report by researchers at the State University of New York at Albany.

The report, "Black Diversity in Metropolitan America," said Afro-Caribbeans stay in school for an average of 12.8 years, compared with 12.5 for black Americans. African immigrants, most of whom live in the Washington area, stay in school an average of 14.5 years, a level that is "higher than [the level for] whites and Asians," according to the report.

"The main routes to America for Africans is through institutions of education," said John Logan, director of the Lewis Mumford Center for Comparative Urban and Regional Research and author of the report. Africans and Afro-Caribbeans are often higher wage earners in their impoverished native countries who emigrate for education and employment opportunities, Logan said.

But Ron Walters, a political science professor at the University of Maryland, said the per-capita wage and education levels among Africans and Afro-Caribbeans are higher because so few of them are allowed into the country.

"It reflects the racism in U.S. immigration policy," Walters said. "If they allowed Africans and West Indians to immigrate in the same numbers they allow Vietnamese, their income and educational averages would fall."

The report, released last month, did not include black immigrants from Spanish- and Portuguese-speaking countries. Those groups are difficult to define racially, Logan said, because Latinos with noticeable African ancestry rarely identify themselves as black.

America's black community, long considered to be a monolithic group with shared cultural and political goals, includes 1.5 million Afro-Caribbeans. They outnumber Cuban and Korean immigrants. Afro-Caribbeans settle mostly in New York, Miami, Fort Lauderdale and Boston.

Nearly 70 percent of the Afro-Caribbeans living in the United States were born overseas, earned a median household income of $40,000 and attended school an average of 12.8 years, according to figures from the 2000 Census.

The number of Africans in the United States passed the half-million mark during the 1990s, with a population that was 85 percent foreign-born. Their median household income was $40,300. Africans from Ghana, Nigeria, Somalia and Ethiopia largely settle in Washington, New York and Atlanta.

African Americans had a median household income of $33,500 and attended school an average of 12.5 years. Their unemployment rate was 9.9 percent, while unemployment among Afro-Caribbeans and Africans was 7.3 percent and 5.1 percent, respectively.

Asians living in the United States earned a median household income of $64,000 and remained in school an average of 13.9 years. Among Hispanics, those numbers were $37,600 and 10.7 years in school, the report said.

Among white people, they were $52,000 and 13.5 years.

"The numbers clearly reflect selective immigration," said Roderick Harrison, a demographer at the Joint Center for Political and Economic Studies. "Immigration laws are skewed across race and ethnic groups toward highly educated immigrants.

"It takes a certain kind of ambition or risk to say 'I'm going to leave Nigeria or Jamaica and strike out for the United States, leaving behind family roots,' " Harrison said. "You're talking about a particularly elite group of people. This is an old pattern that's just being noticed because the numbers are getting a little higher."

Despite their differences in earning and education, black immigrants and African Americans tend to live in urban communities that are segregated from white areas, according to a previous study by the Mumford Center.

That study, "Separate but Unequal: The Neighborhood Gap for Blacks and Hispanics," found that black families with incomes of more than $60,000 tended to live in communities with higher poverty rates than white families with incomes of less than $30,000.

"I certainly interpret this as showing the very strong constraints on where African Americans [and black immigrants] are able to choose to live," Logan said.

Although black groups live near each other, "this does not mean they share the same neighborhoods," Logan said. "Segregation among black ethnic groups reflects important social differences between them."

Those differences have sometimes shown up as conflicts between groups, but that is nothing new, Logan said.

Conflicts between native-born Americans and new immigrants predate the Civil War. White Americans, for example, once thought of Irish immigrants as an inferior race. Similar insults were leveled at Italian and Jewish immigrants near the turn of the last century.

"I think there is some conflict, but there's a potential source for solidarity among these groups," Logan said. "Their children play in the same streets and at the same parks, and they both suffer from the great disparity between white and black groups."