We consider an auction design problem where a seller sells multiple homogeneous items to a set of connected buyers. Each buyer only knows the buyers she directly connects with and has a diminishing marginal utility valuation for the items. The seller initially only connects to some buyers who can be directly invited to the sale by the seller. Our goal is to design an auction to incentivize the buyers who are aware of the auction to further invite their neighbors to join the auction. This is challenging because the buyers are competing for the items and they would not invite each other by default. Thus, rewards need to be given to buyers who diffuse information, but the rewards should be carefully designed to guarantee both invitation incentives and the seller's revenue. Solutions have been proposed recently for the settings where each buyer requires at most one unit and demonstrated the difficulties of the design. We move this forward to propose the very first diffusion auction for the multi-unit demand settings to improve both the social welfare and the seller's revenue.

翻译：本文研究一个拍卖设计问题：卖家向一组互相关联的买家出售多个同质物品。每个买家仅知晓其直接连接的买家，且对物品具有递减边际效用估值。卖家最初仅与部分买家建立连接，这些买家可由卖家直接邀请参与销售。我们的目标是设计一种拍卖机制，激励已知晓拍卖的买家进一步邀请其邻居参与竞拍。由于买家之间存在物品竞争，他们默认不会互相邀请，这构成了设计挑战。因此，需向传播信息的买家提供奖励，但奖励需精心设计以兼顾邀请激励与卖家收益。已有研究针对每位买家最多需求一个单位的情形提出了解决方案，并揭示了设计难点。在此基础上，我们提出首个针对多单位需求场景的扩散拍卖机制，旨在同时提升社会福利与卖家收益。