I think it's best to take program rankings with a grain of salt. Don't get me wrong; not trying to discount the Ivies or the like, just offering an insight. Several of the factors that go into determining rankings may not do their respecctive schools justice.

For example, anyone in America knows that Harvard is attended by mostly the best and the brightest American youth. The graduates of its business school would be no different. The question becomes, how do we define success? One such qualifier is average salary upon graduation. Most Harvard graduates will be making very good money upon graduation. And in most cases, I'll assume, this is because they deserve it. But Harvard students also tend to be some of the most well-connected and financially well-supported students. And such support, and such connections, as you all know, can be just as effective at landing the aforementioned high-paying job.

In other words, business schools can be attributed with causing the success of a student who needed very little of its help to begin with.

Other factors that go into some business rankings are things like the "peer assesment," which are stats tabulated by taking the subjective evaluation of a school by either field professionals or other members of academia.

Basically - the rankings are pretty good indicators of where the best programs are. But they also reflect the inherent likelihood that students that attend expensive schools will be successful and the somtimes biased assesments of a given school - for better or for worse.