From his keynote speech in Mexico City, Michael Clemens writes: Mexico and the United States need a bilateral agreement to regulate the labor migration flows between these two neighboring countries. They have needed such an agreement my entire life.

US development policy was built for a world that no longer exists. When the US Agency for International Development (USAID) was created in 1961, foreign aid was by far the most important flow of resources to developing countries. Today, aid is a relative sideshow. International migrants send roug...