This shift in America’s immigration population, based on census data, is summarized in a report released Thursday by the Brookings Institution. It found that 30 percent of the country’s working-age immigrants, regardless of legal status, have at least a bachelor’s degree, while 28 percent lack a high school diploma.

The shift had been in the works for the past three decades, a period that has seen a dramatic increase in the population born outside the United States. But in 2007 the percentage of highly skilled workers overtook that of lower-skilled workers…

“It seems, based on this and other studies, that we’ve got an oversupply of highly skilled workers coming into this country,” he said, adding that the study’s findings were not surprising. “New college graduates are faring very poorly on the labor market, and what the report is telling us is that we’re bringing in a high number of workers to compete with them.”