Re: Cause or effect
So the implication is that studios should be paying the filesharers for the benefit they confer?
Not necessarily. The research does seem to back up the idea that file sharing can act as publicity: whether it's because people dislike screeners (I can't stand them myself) or subsequently decide to watch a film on the big screen or both.
However, one thing file sharing definitely does is displace activity: if you're watching something you've torrented you're not doing something else (such as watching the same item on DVD or TV or out down the pub with your mates). In fact, in many countries torrents of Hollywood films have displaced local films.
Hollywood has for years been griping about sales lost to piracy, and got some nice laws drafted for its efforts, but it has also been far more positive about digital downloads than the music industry. Both have suffered more from expected incomes from format shifts (remember all the CDs we bought for vinyl or DVDs of VHS we already had?) failing to materialise. In music this was coupled with some stupid contracts and artists rediscovering concerts (previously a means to publicise records, now highly lucrative events not least because the record companies were cut out). Hollywood has profited from the proliferation of TV channels as additional means of distribution in the digital age but failed to see those channels as potential threats: HBO, et al. have for years been producing better quality fare of their own and have become more interesting for artists.