In 1993, the debate heated up in the United States about the North American Free Trade Agreement (NAFTA), which proposed to reduce barriers to trade (such as taxes on or limits to imports) among Canada, the United States, and Mexico

Some people opposed strongly the agreement, arguing that an influx of foreign goods under NAFTA would disrupt the U.S. economy, harm domestic industries, and throw American workers out of work. How might a classical economist respond to these concerns? Would you expect a Keynesian economist to be more or less sympathetic to these concerns than the classical economist? Why?

A classical economist might argue that the economy would work more efficiently with NAFTA because it reduces trade barriers, making the invisible hand work even better. Workers could specialize even more than before so that total output produced by all three countries would be more. Though the industrial mix might change in each country, wages and prices across industries would adjust quickly, and people in industries that closed down in a particular country would quickly find new jobs.
A Keynesian economist might be more sympathetic to concerns about NAFTA because of the belief that adjustment to the changes will not occur quickly. As a result, people in particular industries in a country may become unemployed. Wages won't adjust quickly to restore full employment, so some government action (like retraining programs to give displaced workers new skills) may be desirable.