Debacles on the Border: Five Decades of Fact-Free Immigration Policy.

Since 1987 the Mexican Migration Project (MMP) has compiled extensive data on the characteristics and behavior of documented and undocumented migrants to the United States and made them publicly available to users to test theories of international migration and evaluate U.S. immigration and border policies. Findings based on these data have been plentiful, but have also routinely been ignored by political leaders who instead continue to pursue policies with widely documented, counterproductive effects. In this article we review prior studies based on MMP data to document these effects. We also use official statistics to document circumstances on the border today, and draw on articles in this volume to underscore the huge gap between U.S. policies and the realities of immigration. Despite that net positive undocumented Mexican migration to the U.S. ended more than a decade ago, the Trump administration continues to demand the construction of a border wall and persists in treating Central American arrivals as criminals rather than asylum seekers, thus transforming what is essentially a humanitarian problem into an immigration crisis.