Abstract: Attempts by Members of Congress to save U.S. manufacturing jobs by restricting international trade, particularly with China, are misguided and futile. Technological improvements, not international trade, are reducing U.S. manufacturing employment by automating many rote tasks. During the past decade, manufacturing employment has fallen by one-third while manufacturing output has remained roughly constant.
http://www.heritage.org/research/reports/2010/10/technology-explains-drop-in-manufacturing-jobs