The global recession may be almost over but the debate rumbles on. How much were MBA-trained executives really to blame?

As MBA professors, we heard arguments that we had been teaching the wrong models, neglecting ethics, forgetting common sense, sitting in ivory towers made of spreadsheets and generally nurturing greed. We listened to the charge that business schools were guilty of short-term thinking, especially when evaluating leadership. MBA graduates, so the argument went, were looking for quick riches.

So, when we came up with the idea of a ranking of chief executives based on performance over an entire career, we also decided to check the myth of the value -destroying MBA against a large and meticulously compiled data set.