here's an article about what has happened since:
"Strumpf, 35, and a Harvard University colleague concluded that online file sharing doesn't hurt music sales, contrary to contentions of the nation's recording industry executives.
The industry's trade group began a counteroffensive, blasting the paper as incomplete and flawed."
of course, the true joy of this site is the link to strumpf's paper--which i'd already been shown to by andyhat--where the paper is, as well as a three minute audio of mr burns reading it. 'cause it's in rm format, i haven't downloaded it, but if someone knows of a different format (or indeed has a different format), let me know.
A longstanding economic question is the appropriate level of protection for intellectual property. The Internet has drastically lowered the cost of copying information goods and provides a natural crucible to assess the implications of reduced protection. We consider the specific case of file sharing and its effect on the legal sales of music. A dataset containing 0.01% of the world's downloads is matched to U.S. sales data for a large number of albums. To establish causality, downloads are instrumented using technical features related to file sharing, such as network congestion or song length, as well as international school holidays. Downloads have an effect on sales which is statistically indistinguishable from zero, despite rather precise estimates. Moreover, these estimates are of moderate economic significance and are inconsistent with claims that file sharing is the primary reason for the recent decline in music sales.