In a very tongue in cheek sense of humor, The Peter Principle explains the how and why that if a person stays within a hierarchy long enough they will eventually be promoted to their level of incompetence. Think about it, if you are doing a good job at your current position, it will make you eligible for promotion. This can continue until you hit the level where you are no longer doing a good job. The final chapter also describes how one can avoid being promoted to that level without being fired.
