Mexicans in the United States

So many of the people we meet here claim to have lived in the United States that I was beginning to wonder if some of them were lying. Then I read this in a recent article in the Economist about business in Mexico: 

Mexico is unusual in that it not only has a globalised elite but also a globalised peasantry. The rich study in the United States; the poor mop floors there. Both groups benefit their homeland. The elite pick up skills and contacts at American universities, which help Mexican firms do business with their giant neighbour. Migrant mop-wielders send money home to poor Mexican villages. The scale of border-straddling is colossal. One Mexican in ten lives in the United States—some 12m people. Add in the descendants of Mexicans born in the United States and the number is 33m. This creates a market for Mexican products: Corona is the most popular imported beer north of the border.