<P> In 2015, the Congressional Research Service concluded that 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 ." The report also estimated that NAFTA added $80 billion to the US economy since its implementation, equivalent to a 0.5% increase in US GDP . </P> <P> The U.S. Chamber of Commerce credits NAFTA with increasing U.S. trade in goods and services with Canada and Mexico from $337 billion in 1993 to $1.2 trillion in 2011, while the AFL - CIO blames the agreement for sending 700,000 American manufacturing jobs to Mexico over that time . </P> <P> University of California, San Diego economics professor Gordon Hanson has said that NAFTA helped the U.S. compete against China and therefore saved U.S. jobs . While some jobs were lost to Mexico as a result of NAFTA, considerably more would have been lost to China if not for NAFTA . </P> <P> The U.S. had a trade surplus with NAFTA countries of $28.3 billion for services in 2009 and a trade deficit of $94.6 billion (36.4% annual increase) for goods in 2010 . This trade deficit accounted for 26.8 percent of all U.S. goods trade deficit . </P>

Which of the following groups of countries are members of nafta