** Cross-Posted ** Thomas, Chuck & McDonald, Robert H. (2007) Measuring and Comparing Participation Patterns in Digital Repositories: Repositories by the Numbers, Part 1. D-lib Magazine 13 (9/10) http://www.dlib.org/dlib/september07/mcdonald/09mcdonald.html doi:10.1045/september2007-mcdonald
EXCERPT: "As for mandatory-deposit repositories, the limited available data indicate authors represented in such repositories tend to contribute more of their intellectual output. Sale (2006) predicted institutions establishing deposit mandates were likely to see such results within three years of implementing these policies... This study's findings only reinforce such predictions and arguments favoring institutional mandates. As the data in this article show, a mandate is arguably the "tipping point" described by Gladwell (2000) that can make depositing behavior among scholars not just widespread, but also more of an ingrained and complete behavior."