An interesting 80-second video by Johan Norberg, executive director of Free To Choose Media and senior fellow at the Cato Institute, makes the case that trade agreements have not led to the deindustrialization of America. He notes that the share of U.S. workers employed in manufacturing has been falling at an average of 0.4 percent per year from 2000 to 2010, but it also fell at that same rate between 1960 and 2000. Thus, NAFTA and other trade agreements don’t seem to have had a great deal of influence on the gradual evolution of the economy away from employment in manufacturing and toward employment in services.

If he had more time, Norberg also might have pointed out that the U.S. manufacturing sector has never been larger. Value added by the U.S. factories reached an all-time high of $2.4 trillion in 2015. Manufacturing accounts for about 13 percent of GDP.

Yes, it’s true – fewer people work in manufacturing today than in the past. Peak U.S. manufacturing employment was 19.4 million workers in 1979, but has generally trended downward since then. Today only around 12 million people work for manufacturers, a decline of roughly one third over the past 35 years. Productivity has risen so much that many fewer workers now produce many more manufactured products.

A recent study by the Center for Business and Economic Research at Ball State University found that trade has had some effect on manufacturing employment. Researchers estimate that approximately 13 percent of manufacturing job losses have been due to trade. But the dominant factor has been productivity growth, which accounted for 85 percent of the employment decline. (Robots and computers ate the jobs.) So imports bear a relatively small degree of responsibility for the reduction in manufacturing employment, but take a large share of the blame from politicians.

There are a lot of good things that can be said about U.S. manufacturing. Workers are better educated, better paid, use more sophisticated equipment, and produce more high-value goods. Our country may produce fewer shirts and tennis shoes than before, but we produce more valuable items such as airplanes, motor vehicles, and industrial equipment. So even though there is an abundance of good news for manufacturers, don’t expect to hear much about it in this particularly anti-trade political season.

(A more detailed review of the economic effects of trade agreements can be found in this study by the U.S. International Trade Commission.)