The number of undocumented immigrants living in Washington and across the United States stabilized over the past several years following steady increases for about 15 years before that, the Pew Hispanic Center reported Tuesday.
The country's undocumented population in 2008 was estimated at 11.9 million people, including 7 million who immigrated from Mexico, the report said.
The Pew Hispanic Center, a nonpartisan research organization, estimated 140,000 to 210,000 undocumented immigrants lived in Washington in 2008, making up 2.1 percent to 3.2 percent of the overall population.
That compares with state estimates by various other sources in the past of 210,000 undocumented immigrants in 2005, 160,000 in 2000 and 40,000 in 1990, according to the report.
The report's latest estimates were based on 2008 survey data by the U.S. Census Bureau that were analyzed by Pew's demographers.
The report drew no conclusions about why illegal immigration apparently leveled off in recent years. One of the report's authors, Jeffrey Passel, said it would be difficult to pinpoint border enforcement or a struggling U.S. economy as more of a cause than another.
But at least anecdotally, border enforcement seems to have made it harder to come into the country or leave it, said Carlos Olivares, chief executive officer of the Yakima Valley Farmworkers Clinic.
The clinic used to see a drop in business during the winter when field workers and their families returned to Mexico. But for the last year or two, business has stayed steady even during those months, Olivares said.
"We are seeing less and less people migrate back and forth between the United States and Mexico," he said. "... I think a lot of that has to do with the issues around immigration enforcement."
While the Pew report didn't address immigration policy, its data illustrated the difficulty in crafting such policies.
Across the nation, the report said, undocumented immigrants had 5.5 million children, of whom 1.5 million were undocumented and 4 million were U.S.-born citizens.
Passel said, "We may be able to fit people into boxes of 'undocumented,' 'legal,' 'legal-temporary,' 'U.S. citizens.' It's not so easy to fit families into that same set of little boxes."
Forty-seven percent of undocumented immigrants' households consisted of a couple with children, compared with 21 percent among the U.S.-born population.
Undocumented residents' homes generally had more workers per household, 1.75, as compared with 1.23 for U.S.-born households.
Yet the median income for undocumented immigrant households in 2007 was $36,000, about $14,000 less than the median income for U.S.-born households.
The income disparity was largely due to different education levels between the populations, and it contributed to a greater lack of health insurance among undocumented immigrants, the report indicated.
Forty percent of undocumented immigrants age 18 to 24 hadn't completed high school, compared with 8 percent of U.S.-born people in that age group. Of undocumented residents age 25 to 64, only 4 percent had college degrees.
Undocumented workers generally were concentrated in agriculture, production, construction and the service industry. Many also found employment as groundskeepers, maintenance workers, brick masons, drywall installers, dishwashers, maids, housekeepers and parking lot attendants.
Olivares said he sees employment in such jobs as a sign that immigrants are gradually moving into better jobs and not just working in farm fields. Education will create even better employment opportunities for their children, which will benefit society as a whole, he said.
"The bulk of the population is law-abiding -- actually, law-fearing -- groups who pay their taxes, live a decent life and try to make the best they can for the benefit of the community and their children," Olivares said.
The report found that the younger an undocumented person was when he or she came into the United States, the more likely the person was to have higher education. Of those age 18 to 24 who had completed high school, half were in college or had attended college.
But undocumented immigrants from Mexico generally were less educated and had lower incomes than those from other countries.
In addition to the 7 million undocumented immigrants from Mexico, an estimated 1.3 million were from Central America, 775,000 were from South America, 500,000 were from the Caribbean, 1.3 million were from South and East Asia and 190,000 were from the Middle East.
* Joe Chapman: 509-582-1512; email@example.com