Belief aggregation, updating and dynamic collective choice
从决策理论角度研究允许一致更新聚合信念的方法，提出只适用于一步前瞻不确定性的弱帕累托公理，并证明在二叉树域中取中位数信念满足该公理，动态投票可实现它。
This paper decision-theoretically investigates the belief aggregation method which allows consistently updating the aggregate belief. \n \nAfter confirming that the Pareto axiom and dynamic consistency require the decision power of an individual to evolve proportionally to how much his/her prior has been successful, we propose a weaker Pareto axiom that applies only to one-step-ahead uncertainties and puts no restriction on how the decision powers should evolve. \n \nWe show in the binary tree domain that taking the median belief satisfies the proposed axiom, even full ex-ante efficiency under a single-crossing condition and that dynamic voting implements it. \n \nFinally, we investigate the role of ambiguity aversion.