COPYCENSE

According to a News.com story, researchers at Harvard University and the University of North Carolina tracked music downloads for more than four months in 2002, matching data on file transfers with actual market performance of the songs and albums being downloaded. The conclusion? "Even high levels of file-swapping seemed to translate into an effect on album sales that was "statistically indistinguishable from zero," they wrote. 

"We find that file sharing has only had a limited effect on record sales," wrote the study’s authors wrote. "While downloads occur on a vast scale, most users are likely individuals who would not have bought the album even in the absence of file sharing."

John Borland. Music Sharing Doesn’t Kill CD Sales, Study Says. News.com. March 29, 2004.

Felix Oberholzer and Koleman Strumpf. The Effect of File Sharing on Record Sales: An Empirical Analysis. (.pdf).