The article quoted below provides additional signs that institutions of knowledge production and dissemination may be changing in important ways. (Wikipedia is another, even bigger, sign.)
(p. 635) Over the past decade, there has been a decline in the fraction of papers in top economics journals written by economists from the highest-ranked economics departments. This paper documents this fact and uses additional data on publications and citations to assess various potential explanations. Several observations are consistent with the hypothesis that the Internet improves the ability of high-profile authors to disseminate their research without going through the traditional peer-review process.
Ellison, Glenn. “Is Peer Review in Decline?” Economic Inquiry 49, no. 3 (July 2011): 635-57.