Two large but separate bodies of literature analyze the economic effects of international trade and immigration. Given that several factors are important determinants of both trade and migration flows, the previous studies are vulnerable to a potentially serious omitted-variables bias,...

As of 2004 California employed almost 30% of all foreign born workers in the U.S. and was the state with the largest percentage of immigrants in the labor force. It also received a very large number of Mexican and uneducated immigrants during the recent decades. If immigration harms the labor...