The influx of Mexicans to the United States stops

Through this article of the New York Times, Douglas S. Massey, co-director of the Mexican Migration Project at Princeton says that interest of Mexicans go to America to seek a better job had fallen to its lowest levels since 1950. Also for the first time in 60 years, net illegal migration has gone to zero and is probably negative. Perhaps these results are reflected in the increase of 4 million people in the Mexican census of 2010. The article describes the possible reasons for this stagnation.