时间：2022年6月2日 14:30

地点：邵逸夫科学馆东二层第六会议室

主讲人一：马伟

题目：Random Choice and Social Aggregation

摘要：This paper studies social aggregation of random individual preferences. Given a set of objects of choice, a menu is a nonempty finite set of objects, and a random choice rule specifies the probability distribution of choices from each menu. Assume that all individuals in society and society itself are each endowed with a random choice rule which can be represented by a random utility function. We propose a stochastic analogue of the standard Pareto-weak condition, asserting that if every individual's choice probability of an object from a menu is at least as high as that of another, then so is society's. This formulation takes the empirically observable quantity, choice frequency, as primitive. We show the stochastic Pareto-weak condition holds if and only if the random utility function of society is a convex combination of those of the individuals. We then apply the result to demonstrate that it is possible to linearly aggregate random expected, random dual expected, and random subjective expected utility preferences. The result on random expected utility can be seen as an extension of Harsanyi's aggregation theorem, and has an implication for the probit model. Results on the latter two theories are in contrast to their counterparts in the context of deterministic preferences, wherein it is impossible to aggregate rank-dependent expected utility preferences in a linear way, and all individuals and society conforming to subjective expected utility is not consistent with the standard Pareto condition. The results of the present paper indicate that those negative results are not robust to randomness in preference.

主讲人二：彭长桂

题目：经济学隐喻及其理论意义