Ed Felten has two interesting posts (link via Boing Boing): the first is on Eric Boorstin's Princeton thesis, Music Sales in the Age of File Sharing.
For people in the 15-24 age group, he found a significant negative correlation between Internet adoption and CD sales. For people in all of the age groups older than 25, he found the opposite – a significant positive correlation between Internet adoption and CD sales. Overall, the correlation was significantly positive – metro areas with higher rates of Internet adoption had significantly higher CD sales.The explanation cannot be that higher income predicts both Internet adoption and CD sales; remember that Eric controlled for differences in income. There must be something about Internet access, other than income, that correlates with CD purchasing. Perhaps it's filesharing; perhaps it's something else; or perhaps it's a combination of both.
And today, he puts forward his "Grand Unified theory of File-Sharing", which takes into account survey-based studies and the study conducted by Oberholzer and Strumpf discussed in an earlier post on my teaching-related weblog, as well as the work of Boorstin:
The Boorstin study had different results for different age groups. His 15-24 age group was mostly Free-riders, who buy fewer CDs when they have Internet access, because their filesharing substitutes for purchases. His older age groups were mostly Samplers, who buy more CDs because of filesharing, and who are also, because of their high level of cultural engagement, predisposed to both Internet usage and CD purchasing. Therefore he found that young Internet users buy fewer CDs, while older Internet users buy a lot more.The theory says that the net effect of filesharing on CD sales is roughly zero, because of a balance between the negative impact of the Free-riders and the positive impact of the Samplers. But what happens in the future? It all depends on what happens to today's Free-riders.

