This concluding chapter considers three related matters: perverse effects, advice, and arguments. Perverse effects of yardstick competition are a serious possibility. They may take different forms, but in all cases, they justify some reluctance to derive and formulate recommendations. But, abstaining from giving any advice does not imply policy irrelevance. The uncovering of yardstick competition as a possibly important mechanism should play a role mainly as an argument in political economy debates. This suggestion is in agreement with a methodological position relating three concepts undervalued for a long time in the philosophy of science: models, as imaginary non-linguistic entities; mechanisms, as ingredients both of models and of reality; and arguments, in particular when critical of established views.