In the decade from 2000 to 2010, the Mexican-American population grew by 7.2 million as a result of births and 4.2 million as a result of new immigrant arrivals. This new trend — true of all Hispanic-American populations — means in contrast with the previous two decades, births have overtaken immigration as the main driver of the dynamic growth in the U.S. Hispanic population. The current surge in births among Mexican-Americans is largely attributable to the immigration wave that has brought more than 10 million immigrants to the U.S. from Mexico since 1970. At the same time, Mexican government data shows that the number of Mexicans annually leaving Mexico for the U.S. declined from more than one million in 2006 to 404,000 in 2010 — a 60% reduction. The decline in immigration to the U.S. is due in part to fewer job opportunities, increased border enforcement and recent strong economic growth in Mexico. Read More

Russell Heimlich  is a former web developer at Pew Research Center.