Preference Monotonicity and Information Aggregation in Elections
研究了当选民偏好依赖于有噪音的状态变量时，大型选举能否聚合信息并产生如同状态为共同知识时的结果。发现除非偏好严格符合陪审团隐喻，否则信息聚合无法保证。
If voter preferences depend on a noisy state variable, under what conditions do large elections deliver outcomes "as if" the state were common knowledge? While the existing literature models elections using the jury metaphor where a change in information regarding the state induces all voters to switch in favor of only one alternative, we allow for more general preferences where a change in information can induce a switch in favor of either alternative. We show that information is aggregated for any voting rule if, for a randomly chosen voter, the probability of switching in favor of one alternative is strictly greater than the probability of switching away from that alternative for any given change in belief over states. If the preference distribution violates this condition, there exist equilibria that produce outcomes different from the full information outcome with high probability for large classes of voting rules. In other words, unless preferences closely conform to the jury metaphor, information aggregation is not guaranteed to obtain.