A HBS and UNC Chapel Hill study comparing file-sharing downloads to music sales data supports what several people outside of the recording industry have been saying for a while: file sharing isn’t what’s hurting music sales (thanks to Cory at BoingBoing for the pointer):
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.
As Dan Gillmor points out, the more likely reason music sales are slagging is lousy music and the cartelization of record distribution and radio airplay.