This is the only link I still have online. We researched it extensively when VC Stump first "suggested" deferred rush. The rest I compiled from lexis nexis of which I have hard copies. If you really want the information, send me a message and I can give you more resources, but the overall finding is that there is a small correlation between deferred rush and improved freshman year gpa's, but that's about it. Alcohol culture is alcohol culture whether your house has letters on it or not.
http://greeks.unc.edu/orgs/chancello...tment_1996.pdf