Your question is interesting and one which many people ask themselves. I think it's more like people have one wallet to use and instead of spending money on music they kind of like they spend it on other things - just because they can get it by downloading. The total economic output is however more or less constant. I can only refer to my own spending statistics so feel free to contradict me. I don't put that same money in my savings account! I use it to go to the movies (5 of them past 6 months), fuel my car, go on vacation.
So the recent legislations in e.g. Sweden and the rest of Europe has nothing to do with economics, but rather only distribution of money and "fairness" to the companies. Of course, to succeed they must squash many citizen rights and deploy surveillance to keep citizens in check. One could argue that the win from such legislation really is nothing in comparison of how trampled the citizens become. Of course, the new legislation opens up a can of worms to further reduction of rights sort of like Pandora's box. We end up moving in the wrong direction if what we want is democracy.