Nearly two-thirds of the 10.2 million unauthorized adult immigrants in the United States have lived in this country for at least 10 years according to new estimates by the Pew Hispanic Center, a project of the Pew Research Center.

The analysis finds that 35% of unauthorized adult immigrants have resided in the U.S. for 15 years or more; 28% for 10 to 14 years; 22% for 5 to 9 years; and 15% for less than five years.

The share that has been in the country at least 15 years has more than doubled since 2000, when about one-in-six (16%) unauthorized adult immigrants had lived here for that duration. By the same token, the share of unauthorized adult immigrants who have lived in the country for less than five years has fallen by half during this period—from 32% in 2000 to 15% in 2010.

The rising share of unauthorized immigrants who have been in the U.S. for a long duration reflects the fact that the sharpest growth in this population occurred during the late 1990s and early 2000s—and that the inflow has slowed down significantly in recent years, as the U.S. economy has sputtered and border enforcement has tightened. It also reflects the fact that relatively few long-duration unauthorized immigrants have returned to their countries of origin.

The characteristics of this population have become a source of renewed interest in the wake of former House Speaker (and current Republican presidential candidate) Newt Gingrich’s recent endorsement of a proposal to create a path for unauthorized immigrants to gain legal status. In Gingrich’s plan, special consideration would be given to immigrants if they have lived in the country for a long period of time, have children in the U.S., pay taxes and belong to a church.These length of residence estimates are based on data from the U.S. Census Bureau’s March 2010 Current Population Survey, augmented with the Center’s analysis of the demographic characteristics of the unauthorized immigrant population using a “residual estimation methodology” that the Center has employed for many years. Read More