Law professors Brian Galle and David Walker have just posted to SSRN (free download) a new article identifying a negative association between non-profit executive pay and donor generosity.  That is, according to their study, as we continue to increase the pay of university presidents, we should expect private gifts to the same universities to decline.  I am familiar at least with Brian's prior work, and his scholarship is top-notch, so I am inclined to take this study seriously, as Boards of Trustees should.  Check it out here: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2187979 .