Net Migration from Mexico Falls to Zero—and Perhaps Less April 23, 2012 After four decades that brought 12 million current immigrants -- more than half of whom came illegally -- the net migration flow from Mexico to the United States has stopped and may have reversed. The standstill appears to be the result of many factors, including the weakened U.S. job and housing construction markets, heightened border enforcement, a rise in deportations, the growing dangers associated with illegal border crossings and the long-term decline in Mexico's birth rates. The wave of Mexican immigration to the U.S. could resume as the U.S. economy recovers. But even if doesn't, it has already secured a place in the record books. The U.S. today has more immigrants from Mexico alone than any other country in the world has from all countries of the world. Some 30% of all current U.S. immigrants are Mexican-born. Beyond its size, the most distinctive feature of the modern Mexican wave has been the unprecedented share of immigrants who have come to the U.S. illegally. Just over half (51%) of all current Mexican immigrants are unauthorized, and some 58% of the estimated 11.2 million unauthorized immigrants in the U.S. are Mexican. Read the full report for full details on these subjects: Migration between the U.S. and Mexico Mexicans sent back to Mexico by U.S. authorities U.S. immigration enforcement Mexico, by the numbers Characteristics of Mexican-born immigrants in the U.S.