Rebecca Rosen at The Atlantic writes:

Last year I wrote about some very interesting research being done by Paul J. Heald at the University of Illinois, based on software that crawled Amazon for a random selection of books. At the time, his results were only preliminary, but they were nevertheless startling: There were as many books available from the 1910s as there were from the 2000s. The number of books from the 1850s was double the number available from the 1950s. Why? Copyright protections (which cover titles published in 1923 and after) had squashed the market for books from the middle of the 20th century, keeping those titles off shelves and out of the hands of the reading public.

Go read the whole article, which is accompanied by some alarming charts. You know what? At this point, I don't care about Mickey Mouse. We should urge Congress to pass some law stating that Disney can keep the copyright on all of Walt Disney's characters for ever and ever, if that means they'll allow us to bring sanity back to our copyright system. There are thousands of orphan titles that are currently locked up by copyright. Sure, you can buy used copies if you find them, but without copyright, those books would be in the public domain, ready to find a new life as inspiration for new works. This is how the creative consciousness works; no idea is formed in a vacuum. We find our ideas and inspirations in the great pool of everything that came before. Thanks to copyright laws, we're in the middle of a draught and there's no end in sight.