Northwestern Econ is more prestigious among academic circles (Nemmers Prize), plus you can take classes through the Kellogg certificate program. Northwestern gets alot of attention, because Kellogg gets alot of attention, and corporate attention to Kellogg also trickles down to the undergraduate programs (NU ranks 6th in McKinsey recruiting after Harvard,Yale, Wharton, MIT and Stanford as a recruiter told me).
Cornell has name recognition in that it is an ivy league, Northwestern has name recognition despite standing alone as a Big10 school, but also carries name recognition from its business school, Kellogg.