Yep, yet more comparisons of apples and oranges.
I'm not sure the US publishers "prefer" paper books at this time, though they are certainly more used to it and realize that ebooks are a major disruption to their current business model.
However, what people constantly fail to realize is that the paper part of books -- including the costs of returns -- are a very small slice of a book's costs. Advances, royalties, marketing, editing and accounting make up the bulk of a book's costs.
Further, consumers essentially demand all the "unsold product" to sit in the store and wait for them to show up. That cost is already part and parcel of the business model. It's not like "40% of their revenues are chucked out the window," whereas digital piracy does mean at least some lost sales.
The
proper comparison, then, is how much they lose from shoplifting compared to genuine lost sales from piracy.