There are two different sorts of promotion. The first is a promotion in rank, where the job you do is fundamentally the same, but you are paid more for it beca

There are two different sorts of promotion. The first is a promotion in rank, where the job you do is fundamentally the same, but you are paid more for it because you're better at it. The second is a promotion in office, where the job you do is fundamentally different, but you are paid more for it because your responsibilities are wider. We get in trouble when we try to use the same mechanism for both. Promotions as incentive in the first case are fine. Promotions in the second are what this paper deals with, and are where the incentive aspect is more problematic.