TY - JOUR
T1 - Walrasian pricing in multi-unit auctions
AU - Brânzei, Simina
AU - Filos-Ratsikas, Aris
AU - Miltersen, Peter Bro
AU - Zeng, Yulong
PY - 2023/9
Y1 - 2023/9
N2 - Multi-unit auctions are a paradigmatic model of resource allocation, where a seller brings multiple units of a good to a set of buyers equipped with monetary budgets. It is well known that Walrasian equilibria do not always exist in this model, however compelling relaxations such as Walrasian envy-free pricing do. We design a best possible envy-free and prior-free mechanism for multi-unit auctions with budgets. When the market is even mildly competitive, the approximation ratios of this mechanism are small constants for both the revenue and welfare objectives, and in fact for welfare the approximation converges to 1 as the market becomes fully competitive. We also give an impossibility theorem, showing that truthfulness requires discarding resources and is thus incompatible with (Pareto) efficiency.
AB - Multi-unit auctions are a paradigmatic model of resource allocation, where a seller brings multiple units of a good to a set of buyers equipped with monetary budgets. It is well known that Walrasian equilibria do not always exist in this model, however compelling relaxations such as Walrasian envy-free pricing do. We design a best possible envy-free and prior-free mechanism for multi-unit auctions with budgets. When the market is even mildly competitive, the approximation ratios of this mechanism are small constants for both the revenue and welfare objectives, and in fact for welfare the approximation converges to 1 as the market becomes fully competitive. We also give an impossibility theorem, showing that truthfulness requires discarding resources and is thus incompatible with (Pareto) efficiency.
KW - Approximation
KW - Mechanism design
KW - Multi-unit auctions
KW - Revenue
KW - Social welfare
UR - http://www.scopus.com/inward/record.url?scp=85162177692&partnerID=8YFLogxK
U2 - 10.1016/j.artint.2023.103961
DO - 10.1016/j.artint.2023.103961
M3 - Journal article
AN - SCOPUS:85162177692
SN - 0004-3702
VL - 322
JO - Artificial Intelligence
JF - Artificial Intelligence
M1 - 103961
ER -