In their May 24, 2017 report, the Congressional Research Service (CRS) wrote that the economic impacts of NAFTA on the U.S. economy were modest. In a 2015 report, the Congressional Research Service summarized multiple studies as follows: "In reality, NAFTA did not cause the huge job losses feared by the critics or the large economic gains predicted by supporters. The net overall effect of NAFTA on the U.S. economy appears to have been relatively modest, primarily because trade with Canada and Mexico accounts for a small percentage of U.S. GDP. However, there were worker and firm adjustment costs as the three countries adjusted to more open trade and investment among their economies."