The Peter Principle captures two stylized facts about hierarchies: first, promotions often placeemployees into jobs for which they are less well suited than for that previously held. Second,demotions are extremely rare...

When treatment effects of active labour market programmes are heterogeneous in anobservable way across the population, the allocation of the unemployed into differentprogrammes becomes a particularly important issue. In this paper, we present a statisticalmodel designed to improve the present...