What evidence has anyone shown that music revenues are down because purchases are being displaced by piracy, as opposed to other reasons like people spending th

What evidence has anyone shown that music revenues are down because purchases are being displaced by piracy, as opposed to other reasons like people spending their entertainment time and money elsewhere (videogames, movies, TV, free content available on the internet), or people no longer buying replacement records or tapes as CDs are more durable, or people not on a format upgrade treadmill since they can easily convert from their CDs to whatever format they want for their MP3 players? I'm sure that some of the decline is due to piracy, but I don't think that you can blame it for the whole thing. Also, I'm not terribly sympathetic to an industry which realized that it was losing sales to piracy, but took 8 years before it actually got around to offering what it's customers were looking for, such that their customers could actually pay for what they wanted. Napster was released in 1999, and while the fact that you could get music for free was nice, what was really appealing was that you could look for any song you wanted, find it instantly, download it, and stick it on your MP3 player. Since then, the music industry tried limiting the catalog of services (like Emusic, which offerred DRM-free MP3 downloads but had a lousy selection), or had incompatible DRM-encrusted services that meant that you would risk losing access to your music collection if you changed computers or MP3 players. It wasn't until Amazon MP3 came around in 2007 offering DRM-free MP3 downloads of a reasonably broad selection that they really offered anything at all competitive with piracy. Spending 8 years training consumers that piracy is not only cheaper, but also easier, more convenient, less hassle, and with a greater selection, and who's surprised that they lost customers in that time frame?