Pew Hispanic Center estimates of illegal immigrants, 2008

The Center, whose estimates of the illegal population and illegal workforce I have posted on the past, estimates that as of March 2008 there were 11.9 million illegal immigrants. That is close to the 11.8 million estimate for 2007 put out the other day by the Department of Homeland Security. Back in 2004, the Center estimated that the workforce participation rate of illegal immigrants was 68%m at 7 million. Applying the same percentage today yields an estimate of 8.1 million illegal workers.
The annual inflow of illegal immigrants has declined from the 800,000 level earlier in this decade to 500,000 since 2005. I believe this is the estimate of in-migration, and does not reflect out-migration.
The Center’s past estimates of the entire illegal population was 8.4 million in 2000 and 11.4 million in 2005.
The Executive Summary:
There were 11.9 million unauthorized immigrants living in the United States in March 2008, according to new Pew Hispanic Center estimates. The size of the unauthorized population appears to have declined since 2007, but this finding is inconclusive because of the margin of error in these estimates.
However, it is clear from the estimates that the unauthorized immigrant population grew more slowly in the period from 2005 to 2008 than it did earlier in the decade.
It also is clear that from 2005 to 2008, the inflow of immigrants who are undocumented fell below that of immigrants who are legal permanent residents. That reverses a trend that began a decade ago. The turnaround appears to have occurred in 2007.

The Pew Hispanic Center also estimates that inflows of unauthorized immigrants
averaged 800,000 a year from 2000 to 2004, but fell to 500,000 a year from 2005
to 2008 with a decreasing year-to-year trend. By contrast, the inflow of legal permanent residents has been relatively steady this decade.
Although the growth of the unauthorized population has slackened, its size has increased by more than 40% since 2000, when it was 8.4 million. In 2005, the Pew Hispanic Center estimated there were 11.1 million undocumented immigrants in the United States. The most recent estimate, 11.9 million, indicates that unauthorized immigrants make up 4% of the U.S. population.
These estimates are based mainly on data from the 2000 Census and the March Current Population Surveys for the years since then. Because the Census Bureau does not ask people their immigration status, these estimates are derived using a widely accepted methodology that essentially subtracts the estimated legal immigrant population from the total foreign-born population. The residual is treated as a source of data on the unauthorized immigrant population.
The estimates are not designed to explain why the net growth rate has declined. There could be a number of possible causes, including a slowdown in U.S. economic growth that has had a disproportionate impact on foreign-born Latino workers, at the same time that economic growth in Mexico and other Latin American countries has been stable. Another factor could be a heightened focus on enforcement of immigration laws, which a recent Pew Hispanic Center survey indicates has generated worry among many Hispanics.
Other major findings:
• Undocumented immigrants make up 30% of the nation’s foreign-born population of more than 39 million people. More than four-in-ten of the nation’s unauthorized immigrants—5.3 million people—have arrived since the decade began.
• The vast majority of undocumented immigrants—four-in-five—come from Latin American countries. In March 2008, 9.6 million unauthorized immigrants from Latin America were living in the United States.
• The number of unauthorized immigrants from Mexico, 7 million, appears to have leveled off since 2007. Mexico remains the birth country of most unauthorized
immigrants in the U.S.
• The number of undocumented immigrants from other Latin American nations has fallen since 2007.