Based on the comment and reply, I modify the Top15 list
First tier: Chicago, Harvard, MIT, Princeton, Stanford, Yale, Berkeley
Second tier: Columbia, Michigan, Minnesota, Northwestern, NYU, Upenn, UCLA, and Wisconsin
Comment on this is also warmly welcomed.
Yes, you are right. With less than 30 faculty, Wisconsin is still in top 30 in the ranking at IDEAS (which isheavily biased towards the number of faculty) , which shows the excellent quality of its faculty and I never believe that Wisconsin is outside top 15. IMO, if it is the same school but at other cities (say, NY), it could be at top10. One of my friend chooses cornell over Wisconsin last year simply due to the fact that Madison has a poorer weather than it is in NY.
But the thing is that 120-150 offers for 20-25 target, almost 100 students reject Wisconsin? I mean if it is top 15, why 100?