Preferences Over Sets of Lotteries1
研究决策者先选一组彩票、再由自然从中选一个的模型，用集合大小表示客观模糊程度，提出公理并推导出按最好和最差彩票期望效用的加权平均来评价集合，权重反映对客观模糊的态度。
This paper studies a model in which in period 1, a decision-maker chooses a set of lotteries and in period 2, Nature chooses a lottery from the set chosen by the decision-maker and the decision-maker consumes the lottery chosen by Nature. Larger sets are interpreted as representing more ambiguous objective information about the lottery that will be consumed. The axioms imposed on preferences over sets of lotteries generalize those often imposed on preferences over single lotteries in the existing literature. A decision-maker who satisfies these axioms evaluates sets of lotteries according to a weighted average of the expected utilities of the best and the worst lottery in a set, with the weights interpreted as a measure of (comparative) attitude to objective ambiguity. Copyright 2007, Wiley-Blackwell.