It's not the first study that claims and practically proves how irrelevant is to say that uncontrolled file sharing'd cripple the music industry.
One of the most relevant studies I have read was in fact issued five years ago already, back in 2002. A former executive of la FNAC (http://en.wikipedia.org/wiki/FNAC), a French competitor to Virgin Megastores, has announced the results of a study based on their sales for the past 20 years. According to this study, it appeared that the French consumer's average budget dedicated to entertainment (in percentage of their income) hadn't significantly changed for almost all this time lapse, independently of inflation. On the other hand, it appeared clearly that the centers of interests (and cash spending) of the brand's customers had drastically spread between the purchase of DVD's, video games, MP3 players, mobile phones, and surprisingly books. Considering that the boom of the CD sales due to the massive purchase in replacement of phonograph records started to be out of breath in the late 90's, coinciding with the birth of the Napster network and premises of online file sharing, here was an undreamed-of scapegoat.
Though similar arguments have been told a countless times, I'd in fact fancy some kind of study that proves the beneficial impact of unlegit music downloading toward shoplifting in record shops. For ages, unemployed teens couldn't afford the money to buy all the music they want right? Stealing a record in a shop *does* cost money to someone, that has nothing to do with the virtual shortfall claimed by the **AA.