Russian roulette: the need for stochastic potential outcomes when utilities depend on counterfactuals
在医学决策中，若将“首先不伤害”原则表达为不对称效用函数（杀人的损失重于救人的收益），会导致决策悖论；通过放弃稳定单位处理值假设、允许潜在结果为随机变量可解决该问题。
Summary It has been proposed in medical decision analysis to express the ‘first, do no harm’ principle as an asymmetric utility function in which the loss from killing a patient would count more than the gain from saving a life. Such a utility depends on unrealized potential outcomes, and we show how this yields a paradoxical decision recommendation in a simple hypothetical example involving games of Russian roulette. The problem is resolved if we abandon the stable unit treatment value assumption and allow the potential outcomes to be random variables. This leads us to conclude that, if you are interested in this sort of asymmetric utility function, you need to move to the stochastic potential outcome framework. We discuss the implications of the choice of parameterization in this setting.