I don't think that it is generally a zero-sum competition, in the sense that every book purchased used means one not purchased new. Were I pinched for money, I

I don't think that it is generally a zero-sum competition, in the sense that every book purchased used means one not purchased new. Were I pinched for money, I might buy at friends of the library sales, I guess. But most of the books I buy used are either out of print or not easily ordered, and generally I wasn't thinking of buying them until I noticed them on the shelf. And a fair bit of what is on the shelves of the regular bookstore is not by living authors, is it? Just about chest level of the rightmost shelf of fiction at Kramerbooks you will see about a foot of the works of Evelyn Waugh, who died about fifty years ago.