JOAQUIN AMARO, Mexico – Decades ago, before massive waves of young men fled north, Pedro Avila Salamanca helped his father harvest corn and fatten pigs. He learned to write his name in a one-room schoolhouse. Sometimes he rode to town on a donkey. It’s all a distant memory now. Everywhere abandoned houses are crumbling. The towns are shrinking. And Avila, 89, who wears donated clothes and lives on the meager checks his daughters send from the United States, can’t remember the last time he ate meat. ‘What would I buy it with?’ he asked. Avila is a part of the immigration debate that neither Mexican political leaders nor cheap-labor advocates in the United States like to talk about: Heavy migration has all but emptied much of the Mexican countryside. Money sent back to Mexico from those working in the United States reached a record high last year, $20 billion, making remittances from migrants Mexico’s second largest source of income, surpassed only by oil exports. But the export of human labor has been devastating here. It’s left the land dotted with near-ghost towns inhabited by the very old and the very young, their lives dependent on whatever […]