According to The Atlantic:
https://www.theatlantic.com/magazine/arc ... ness/8718/ (It's about Mitt Romney)
An Excerpt:
"Now consider what a consultant does. Consultants are, as any firm will tell you, the “best and the brightest,” culled from elite undergraduate and graduate programs. But they rarely lead anything larger than a small team; the average Army second lieutenant nine months out of a third-tier state college probably has more direct reports, and more deliverables.
Moreover, a consultant’s voice is not the voice of direct experience; most of the problems that consultants analyze are ones they have never faced. And although consultants asking for your business may talk about the trove of industry intelligence they have to share, in practice, the sharing is limited: contracts forbid sharing anything really juicy, and some firms work with only one client per sector at a time. In fact, the arguments for hiring a consultant are often the same as those for seeing a psychiatrist. Both experts have helped an awful lot of people work through problems, which makes them good at listening and gives each one an arsenal of best practices to suggest to their new clients."