http://nepc.colorado.edu/publication/research-that-reaches Holly Yettick's has done some interesting work regarding the influence of traditional, university-based education research versus that of think tanks. Despite universities producing about 15 times as much research as think tanks, they're only cited in the media (sources like the New York Times, Washington Post, and even Education Next) twice as often. I referred to this report in http://blog.mathed.net/2011/10/publication-paradox.html.