Here are some more details from the notes I took during Guttentag’s lecture:
ED admit rate (overall): 23%
ED admit rate (legacy): 35%
RD admit rate (overall): 10%
RD admit rate (legacy): 16%
He also said that Duke considers legacy status regardless of the school their parent attended (Trinity, Pratt, Medicine, Law, Fuqua, etc). But sibling legacy only helps when applying ED.
One question from the audience: does Duke offer legacy advantage as an institutional priority, or because Duke alumni are able to offer better opportunities for their children and hence are better qualified than the regular pool? ANSWER: we have made this a priority based upon institutional desire to admit more alumni children.