source
it's kind of long, here are some interesting points.
"However, our analysis of the Canadian P2P file-sharing subpopulation suggests that there is a strong positive relationship between P2P file-sharing and CD purchasing. That is, among Canadians actually engaged in it, P2P file-sharing increases CD purchasing. We estimate that the effect of one additional P2P download per month is to increase music purchasing by 0.44 CDs per year (based on estimates obtained from the negative binomial model in Table 4.3). Furthermore, we find indirect evidence of the 'market creation' effect of P2P file-sharing in the positive coefficient on the variable 'Not available elsewhere' (Table 4.3)."
"With respect to the influence of price on CD purchasing, we are unable to find any direct relationship between the respondents' reported average CD price and CD purchases in Canada (Table 4.3 and Appendix 4). However, we find some indirect evidence that price influences CD purchasing, as the variable capturing the motivation to engage in P2P file-sharing because of the perception that CDs were too costly was negatively associated with CD purchases."
"Another important finding is that the overall results show that people who purchase paid electronically-delivered music are not less likely to purchase music in traditional markets (CD albums). However, people who also own an MP3 player appear to be less likely to purchase CD albums."