Researchers at the BI Norwegian School of Management conducted a study that concluded that downloading infringing copies of music strongly correlates buying above-average amounts of music. The music industry says that this doesn't prove that downloading from P2P entices people to buy music, and you know what? I think they're kind of right.
The Norwegian study closely matches the findings from a Canadian study a few years ago. Both studies show that people who download a lot buy a lot of music -- and other research and interviews I've conducted suggest that downloading a lot of music is also correlated with doing other music-related stuff, like attending concerts, making mixes for friends, playing music, recording music, and so on.
There's a simple explanation for this: if you really love music, you do lots of music-related things. If you're in the 20 percent of fans that buys 80 percent of records, you're probably in the 20 percent of downloaders that download 80 percent of music, the 20 percent of concertgoers that buy 80 percent of the tickets, and so on. The moral is that music superfans love music and structure their lives around it.
Which means that when the music industry targets "the worst offenders" in its legal campaigns against downloaders, the people they're attacking are the ones who are spending the most on music.
Now, does this mean that downloads end up interfering with sales of music, or not? My guess is that it's a little of both. As Tim O'Reilly wrote, Piracy is Progressive Taxation. Obscure acts probably get more sales than they lose. Modestly well-known acts probably lose and gain about the same. Very famous performers probably lose a little. This has been the conclusion in the quantitative studies in music and books to date, and it makes sense to me.
Unsurprisingly, BI found that those between 15 and 20 are more likely to buy music via paid download than on a physical CD, though most still purchased at least one CD in the last six months. However, when it comes to P2P, it seems that those who wave the pirate flag are the most click-happy on services like the iTunes Store and Amazon MP3. BI said that those who said they download illegal music for "free" bought ten times as much legal music as those who never download music illegally. "The most surprising is that the proportion of paid download is so high," the Google-translated Audun Molde from the Norwegian School of Management told Aftenposten.