What I will say is that while the report may be junk research, the overall claim is not surprising. As I have continually argued, digitization tends towards commodification, and commodities are not valued as highly. The music industry was savaged in the first 10 years of digitization, and while bestselling authors and headlining music acts are doing well, others in those industries are struggling to stay alive. The New York Times has dropped in value (stock value have crept close to "penny stock" level), magazines and journals are closing, and writers of very type are struggling to find a market.
For libraries, this means that we are dealing with a skittish market of content providers. Beset on all sides, writers are looking for friends and allies. Unfortunately, libraries have often taken these content creators for granted, but now is a good time to begin working on new relations and alliances. it is encouraging to know that many authors see us as an ally already, but we should be actively looking for new opportunities like direct purchasing from author's as ways of helping them adapt and position ourselves for long-term survival.