We present a general framework for designing approximately revenue-optimal mechanisms multi-item additive auctions, which applies to both truthful and nontruthful auctions. Given (not necessarily truthful) single-item auction format satisfying certain technical conditions, we run simultaneous item auctions augmented with personalized entry fee each bidder that must be paid before the can access...

Descending price auctions are adopted for goods that must be sold quickly and in private values environments, for instance in flower, fish, and tobacco auctions. In this paper, we introduce ex post efficient descending auctions for two environments: multiple non-identical items and buyers with unit-demand valuations; and multiple identical items and buyers with non-increasing marginal values. O...

There are many benefits for coordination of multiple suppliers when single supplier cannot satisfy buyer demands.  In addition, buyer needs to purchase multiple items in a real supply chain. So, a model that satisfies these requests has many advantages. We extend the existing approaches in the literature that assume all suppliers need to be put on a common replenishment cycle and each supplier ...

A model of English auctions is proposed to incorporate the possibility of jump bidding. When two objects are sold separately via such auctions, bidders signal their willingness to pay via jump bids, thereby forming rational expectations of the prices without relying on any central mediator. Hence a multi-item bidder does not suffer the exposure problem of having to buy an item while he is uncer...