The fair use industries, including consumer device makers, software developers, search engines and news organizations, had US$4.5 trillion in revenue in 2009, up from $3.4 trillion in 2002, according to the study, commissioned by the Computer and Communications Industry (CCIA) Association. Revenue peaked at $4.7 trillion in 2008 and 2009, said the study, by Capital Trade, an economic consulting firm.

Fair use industries in the U.S. employed 17 million people in 2009, about one out of every eight U.S. workers, , released Monday. The employment numbers were down from 17.7 million in 2008.

"The fair use economy really held its own" during the recent recession, said Andrew Szamosszegi, co-author of the study.

Fair use businesses make up about 17 percent of the U.S. gross domestic product, according to the study.

The study shows the importance of fair use exceptions in copyright law, said Ed Black, CCIA's president and CEO. While the entertainment industry and other groups push for tougher copyright laws, lawmakers should consider the impact of those laws on fair use and on its economic impact, he said.