Incentive Compatible Budget Elicitation in Multi-unit Auctions

In this paper, we consider the problem of designing incentive compatible auctions for multiple (homogeneous) units of a good, when bidders have private valuations and private budget constraints. When only the valuations are private and the budgets are public, Dobzinski et al [6] show that the adaptive clinching auction is the unique incentive-compatible auction achieving Pareto-optimality. They further show that this auction is not truthful with private budgets, so that there is no deterministic Pareto-optimal auction with private budgets. Our main contribution is to show the following Budget Monotonicity property of this auction: When there is only one infinitely divisible good, a bidder cannot improve her utility by reporting a budget smaller than the truth. This implies that the adaptive clinching auction is incentive compatible when over-reporting the budget is not possible (for instance, when funds must be shown upfront). We can also make reporting larger budgets suboptimal with ...

• Type: Conference
• Year: 2010
• Where: SODA
• Authors: Sayan Bhattacharya, Vincent Conitzer, Kamesh Munagala, Lirong Xia
• Keywords: Adaptive Clinching Auction, Budget Monotonicity Property, Discrete Algorithms, Private Budget Constraints, SODA 2010