Sure, if writers write faster than they can write well, then there will be declines. But thinking about it, many authors I am quite fond of seem to have routin

Sure, if writers write faster than they can write well, then there will be declines. But thinking about it, many authors I am quite fond of seem to have routinely published two or more books a year during their more productive phases. Elizabeth Bear and Charles Stross are two great young SF writers who have done it well for their entire novel-publishing careers. Going back further, Asimov (counting non-fiction) and L'Amour seem to have been that productive for most of their careers, Moorcock and Zelazny for the major portions of them. Thinking over it, I'd say what these authors had in common in their productive period was that they were writing full time and their books were short! I suspect the average page length of the books I counted was 250 pages, maybe as low as 200. Based on that, I'd suggest a good strategy for doubling the number of books you publish in a year without reducing the quality is simply cutting the page count for each book. Honestly, I wouldn't be surprised if that actually raised the quality of the books...