Revenue-Optimal Efficient Mechanism Design with General Type Spaces
Siddharth Prasad, Maria-Florina Balcan, Tuomas Sandholm
TL;DR
The paper addresses revenue-optimal efficient mechanism design when agent type spaces are general and possibly disconnected, where WT can be suboptimal. It develops two equivalent characterizations—the allocation-wise Groves and the component-wise Groves—both supported by a novel network-flow formulation that captures incentive compatibility and individual rationality constraints. The authors show that the revenue-optimal mechanism is unique within these classes and can be computed via shortest-path problems on induced graphs, connecting allocation partitions or connected components to payments. This generalizes beyond connected-type results, broadening the expressive power of agent information (e.g., exclusivity, conditionals, discrete types) and offering a foundation for practical, data-driven design of pricing rules in complex markets.
Abstract
We derive the revenue-optimal efficient (welfare-maximizing) mechanism in a general multidimensional mechanism design setting when type spaces -- that is, the underlying domains from which agents' values come from -- can capture arbitrarily complex informational constraints about the agents. Type spaces can encode information about agents representing, for example, machine learning predictions of agent behavior, institutional knowledge about feasible market outcomes (such as item substitutability or complementarity in auctions), and correlations between multiple agents. Prior work has only dealt with connected type spaces, which are not expressive enough to capture many natural kinds of constraints such as disjunctive constraints. We provide two characterizations of the optimal mechanism based on allocations and connected components; both make use of an underlying network flow structure to the mechanism design. Our results significantly generalize and improve the prior state of the art in revenue-optimal efficient mechanism design. They also considerably expand the scope of what forms of agent information can be expressed and used to improve revenue.
