Citation Analysis of the Effects of Posting to a Preprint Server

David Bigword on Catalogablog calls attention to a very interesting citation analysis. For astrophysical literature, Schwarz and Kennicutt demonstrates that making a paper available on a preprint server doubles the number of citations. The authors wonder if a trend is developing, namely a growing tendency to ignore research not on a preprint server, somewhat like the current tendency to ignore astrophysical research not indexed in online databases?

LIS Research Topic. Of course, there are substantial differences between astrophysical literature and scholarly legal literature but, I bet if one studies the matter, one would reach the conclusion that legal works posted on SSRN are cited more frequently than articles not made accessible on a preprint server. Long exposure would be the major factor, I think. but I doubt the citation rate would be twice that of articles not made available on a preprint server.