Unless I'm totally misunderstanding the numbers, Thor looks like a good thing. Pre-Thor, publishers printed much more than they could sell. Post-Thor, that is a bad approach. They come out better if they do a better job of not going to far over.
The downside is that it diminishes the economic value of titles with long trailing demand, so books go out of print faster.
This reduces the economic value of copyright as well because although the publisher has a monopoly right to print and distribute the work, it has lost the economic incentive to make the work available; yet no one else can either.
