Contextually Private Mechanisms

Haupt and Hitzig introduce a framework for comparing the privacy properties of different mechanism protocols. The core research question is: when a designer commits to implementing a social choice rule, how much superfluous private information must they inevitably learn about agents, and how should they design the elicitation protocol to minimize that exposure?

The setting is a finite-player extensive-form game in which a designer elicits agents’ private types through a dynamic protocol to compute a social choice function. The authors explicitly exclude cryptographic tools and trusted mediators, working under the minimal assumption that the designer learns information if and only if an agent discloses it. This assumption is motivated by the historical prevalence of live dynamic auction formats — ascending formats at Sotheby’s, descending formats at Aalsmeer, oral ascending formats used by the U.S. Forest Service for timber, multi-round clock auctions for radio-spectrum allocation — and by settings where mediating technology is unavailable or costly.

Zoë Hitzig | Macro Paper Warehouse

Contextually Private Mechanisms