[darryl]

I don't think there is any cause to worry about non-fiction. Academia provides a constant stream of titles on many subjects, and also much of the research. Experts or faux experts on subjects seem to have no problems producing books. Neither, unfortunately, do advocates and activists, though their work is ofter better described as fiction.

@Zod. IMHO there may be some books which are not written because of the decline of the system of advances. Though we can never really know, I expect these will be books which have so few potential readers that they would not be viable under any model but patronage.