On rank dominance of tie‐breaking rules
研究了在资源分配中打破平局的彩票规则，证明当资源受欢迎时，所有代理人偏好统一彩票而非独立彩票，并在更一般的嵌套MNL模型下推广了这一结果。
Lotteries are a common way to resolve ties in assignment mechanisms that ration resources. We consider a model with a continuum of agents and a finite set of resources with heterogeneous qualities, where the agents' preferences are generated from a multinomial‐logit (MNL) model based on the resource qualities. We show that all agents prefer a common lottery to independent lotteries at each resource if every resource is popular , meaning that the mass of agents ranking that resource as their first choice exceeds its capacity. We then prove a stronger result where the assumption that every resource is popular is not required and agents' preferences are drawn from a (more general) nested MNL model. By appropriately adapting the notion of popularity to resource types, we show that a hybrid tie‐breaking rule in which the objects in each popular type share a common lottery dominates independent lotteries at each resource.