The fourth-largest group of college-educated immigrants in the U.S. are Mexicans, after immigrants from India, China and the Philippines.

"Much of the U.S. debate on Mexican immigration has focused on low-skilled immigrants, who have long composed the largest share of Mexicans in the United States," wrote the Migration Policy Institute in a report released last week. "Recent data, however, show notable skill-level increases in this population."

The number of Mexican immigrants with a bachelor's degree or higher more than doubled between 2000 and 2017, from 269,000 to 678,000, according to Ariel G. Ruiz Soto and Andrew Selee in "A Profile of Highly Skilled Mexican Immigrants in Texas and the United States."

Nearly 1 in 6 Mexicans arriving between 2013 and 2017 had a college degree, compared with slightly more than 1 in 20 for those coming between 1996 and 2000.

Naturalized citizens made up the largest share (45% nationwide) of Mexican college graduates, "but unauthorized immigrants (30%) and green card holders (21%) are also well represented," the institute's policy paper said.

"Temporary-visa holders were a much smaller share of the total population," the institute wrote, "though they were the group most likely to hold a degree."

Meanwhile, because the Mexican economy has improved, migration to the U.S. from its southern neighbor has slowed. Other factors include stepped up border enforcement on the U.S. side and a drop in Mexico's birth rates.

College-educated Mexicans find work in the U.S. in fields including teaching at all levels, construction, wholesale grocery, hospitals and restaurants.

The report noted that Texas' metropolitan areas -- Houston, Dallas, El Paso, McAllen and San Antonio -- have been a gateway for these college-educated Mexican immigrants, with 27 percent of college-educated Mexicans making their homes there. Highly skilled Mexicans were prevalent in San Antonio, McAllen and El Paso -- urban areas near the U.S.-Mexico border.

"Policies that make language training more accessible and that streamline the requirements for having professional degrees and skill certifications recognized would enable highly skilled immigrants, including those from Mexico, to join the ranks of qualified professionals and contribute more fully to the state and U.S. economies," the report concluded.