Sabe aquele seu amigo que acha os dez princípios da economia enunciados no livro-texto (que muito pterodoxo não leu, sequer, até a metade) do Mankiw? Pois é. Olha aí.
Small cash rewards for big losers : experimental insights into the fight against the obesity epidemic (English)
This paper examines the sustainability of weight loss achieved through cash rewards and, for the first time, the potential of monetary incentives to prevent weight cycling. In a three period randomized controlled trial, about 700 obese persons were assigned to two treatment groups, which were promised different cash rewards contingent on the achievement of an individually assigned target weight, and to a control group. Successful participants were subsequently allocated to two treatment groups offered different monetary incentives for maintaining the previously achieved target weight and to a control group. This is the first experiment of this kind that finds sustainable effects of weight loss rewards on the body weight of the obese even 18 months after the rewards were removed. Additional incentives to maintain an achieved body weight improve the sustainability of weight loss only while are in place
Show de bola, não? Ah sim, um trecho da conclusão (onde ele discute problemas, inclusive o da validação externa…sobre o qual falei em sala, ahá, hoje).
Our experiment shows that financial incentives can have positive and sustainable effects on weight reduction of obese individuals and, hence, may be an effective measure to fight the obese pandemic. According to our results, however, it appears to be important to announce monetary rewards well in advance. Different to the effect of monetary incentives to lose weight, we are not able to provide a clear answer concerning the effects of financial incentives to sustain a certain body weight. At the end of the experiment, individuals who received both incentives for weight loss and incentives to maintain a lower body weight are neither better nor worse off than individuals who received only a weight‐loss reward.
Eu reconheço: minha aula de Econometria III é muito boa! Sem falsa modéstia porque sei bem o meu valor. ^_^
p.s. para uma definição de pterodoxo (termo que eu cunhei, há anos), pesquise este blog.