An interesting blog at A potted history of pen names – National Library of Scotland Blog (  includes a comment relative to this topic. The museum had an exhibit on pen names that ended last spring. In the blog it is noted that "By 1830 around 80% of novels were issued under a pen name or were anonymous. Printers were obliged by law to put their name on the title page of a book, and it was suggested that the law should be extended to make authors publish under their ‘real’ names, but this never happened."