Immigration Accounting: U.S. States 1960-2006

Different U.S. states have been affected by immigration to very different extents in recent years. Immigration increases available workers in a state economy and, because of its composition across education groups, it also increases the relative supply of less educated workers. However, immigration is more than a simple labor supply shock. It brings differentiated skills and more competition to the labor market and it may induce efficient specialization and affect the choice of techniques. Immigrants also affect investments, capital accumulation, and the productivity of more and less educated workers. Using a production function-based procedure and data on gross state product, physical capital and hours worked we analyze the impact of immigration on production factors (capital, more and less educated labor), and productivity over the period 1960-2006 for 50 U.S. states plus D.C. We apply growth accounting techniques to the panel of states in order to identify the changes in factors and productivity associated with immigration. To identify a causal impact we use the part of immigration that is determined by supply shifts in countries of origin and the geographical location of U.S. states or historical immigrants' settlements. We find that immigration significantly increased the relative supply of less educated workers, that it did not affect much the level of capital per worker and that it significantly increased the productivity of highly educated workers and, even more, less educated workers. These channels together explain the small effect of immigrants on wages of less educated workers and the significant positive effects on wages of more educated workers.