The Swiss report is a 13 page meta-analysis with 53 footnotes, many of which are citations of other studies.
> the cost of providing the services doesn't [remain constant]
Actually, you're right. The labor of producing that track is unchanged. The cost of distribution goes down. The cost of the concert is unchanged. So, net cost of 3 minutes of happiness went down.
Yes, this is a key economic truth that seems almost completely missed.
Every pirated copy that is used actually adds value into the economy. It is sort of hilarious how upside-down the usual presentation is: all the figures of so many m/billions of losses are actually more like the opposite, they are gains to the public. The only possible loss anywhere is in reduced production -- but that is never demonstrated.
Copyright and patents exist specifically because the public wants more creative work produced, and at the time, granting temporary exclusive rights appeared to have the net result of enriching the public domain in the long run. They both represented tradeoffs: you can have a temporary monopoly if that gets you to create work that wouldn't otherwise exist, because after a relatively short time your work then becomes part of the public domain.
Those tradeoffs don't necessarily make sense now. The durations have gone up drastically, with no corresponding increase in the value we get. We also lose far more value during that time, because we've reduced the cost of copying to zero, and in the process created an astonishing number of awesome ways to work with media. The durations and rights of copyright should have gone down over the years, because authors can extract value from works more quickly (no 20 year ramp time needed), and because we lose so much by not having a work readily available to merge into our culture sooner; thus, we don't need to trade off as much value to get what we want.
When you see the whole mechanism of artificial scarcity as a society-wide "payment" for what we want, then you start wondering why we pay so much more for so much less, and whether we ought to stop buying entirely.