Now, the one thing that probably helps the numbers of the Big Ten is that even the lowest-ranked schools still have good or even great undergrad business programs (e.g. Indiana is usually one of the lower-ranked overall undergrad schools in the Big Ten, but its undergrad business school is considered to be #2 in the conference after Michigan and among the top 10 in the country). Note that these are solely undergrad numbers, so they're not even including Northwestern's Kellogg School of Business (which doesn't have an undergrad program but churns out as many C-suite executives as anyone in the Ivy League at the MBA level). So, sure, there's a quantity aspect there, but it's also that there's a critical mass of good-to-great undergrad business programs from top-to-bottom in the conference that you don't see in the other P5 leagues. The ACC comes the closest in terms of top-to-bottom depth - the top of the ACC is arguably better than the Big Ten academically, but the bottom half isn't as strong.