To add to what Hitch said, the amount of new material available for publication has risen by leaps and bounds since the 1940s. At one time in the period (1907) in the article there were around 10,000 books available to be put to press in the USA. Now there are millions. No wonder books were reprinted in different editions by various publishers.
http://stuffnobodycaresabout.com/201...ared-to-today/
In the 50's the term slush pile was already starting to be used as publishers had more books than they could deal with. They dis not have to reprint just to stay in business.
In the 1930s authors were starting to publish multiple books and many of these are in print today in both paper and ebook format, and selling well.
Rex Stout is still popular today and his first book was published in 1938.
I am strongly of the opinion that most authors who wrote more than one book did so because they hoped to make money and lots of it. I doubt that Rex Stout, Dorothy Sayers etc. would have been cranking out detective books without copyright. Or Anne McCaffrey, Robert A. Heinlein or Isaac Asimov Sci-Fi.
Without some form of copyright most authors wouldn't write and those that did would not be writing many books. No incentive at all these days.
Not that popular fiction is necessary for world development as the world got along without it prior to the 1920s, but I kind of like it.
And saying that there are less editions of 1940s work says nothing. Existing copies might. Or saying that the amount of reading material is severely limited because publishers can't publish everything from the 1940's on willy nilly is kind of suspect. I doubt they would want to if they could. They publish Rex Stout and many others because people buy the books. They publish James Patterson and his gang and others like them because many many more people buy the books.
And of course if all the popular writers today stopped writing then they would publish more backlist books. They would still expect to be paid for them. Gutenberg or not, changing the terms of copyright is not likely to help anyone much. A few would say wow I can download a so-so copy for free of that book I would have had to save up for months for but how many people have a massive TBR list from the 40s where the price is prohibitive and nothing else will do?
Helen