Return to Answer

The MPAA also seemed to assume this according to Wikipedia. I wasn't able to access the references where the claim allegedly came from.

The MPAA's estimate was doubted by commentators since it was based on the assumption that one download was equivalent to one lost sale, and downloaders might not purchase the movie if illegal downloading was not an option.

Source: http://en.wikipedia.org/wiki/Peer-to-peer_file_sharing#Economic_Impact_on_the_film_industry

Evidence against such claims

Evidence against such claims

• A report from the IFPI in 2009 nestimates that 95% of msuci downlaods are illegal, and that only 10% of that 95% can be considered a lost sale.

• A report from the IFPI in 2009 estimates that 95% of music downloads are illegal, and that only 10% of that 95% can be considered a lost sale.

Our analysis also suggests that a lack of DRM protection can increase industry profits, even though it hurts the profitability of traditional music retailers.

Source: Downloadable Music Set Free: The Flip Side of DRM Protection