[Paper by Paul Heald] This study compares the availability of books whose copyrights are eligible for statutory reversion under US law with books whose copyrights are still exercised by the original publisher. It finds that 17 USC § 203, which permits reversion to authors in year 35 after publication, and 17 USC § 304, which permits reversion 56 years after publication, significantly increase in-print status for important classes of books.