Unauthorized migration is a major issue in the United States and many other countries, sometimes generating intense publicity and debate. How can leaders minimize the "push" factors that encourage this type of migration? Trade, investment, and foreign aid, for example, might help create jobs and opportunities in the sending countries that would keep potential migrants home. But do these strategies help slow unauthorized migration? In this PRB Discuss Online, Phil Martin, professor of agricultural economics at the University of California, Davis, and a noted expert on international labor migration, answered participants questions on this topic. Read a transcript of the questions and answers. (March 2008)