Budget-constrained Bidders Research Articles

A note on the impossibility of multi-unit auctions with budget-constrained bidders

A note on the impossibility of multi-unit auctions with budget-constrained bidders

Auction design and order of sale with budget-constrained bidders

The presence of financial constraints changes traditional auction theory predictions. In the case of multiple items, such constraints may affect revenue equivalence and efficiency of different auction formats. We consider a simple complete information setting with three financially constrained bidders and two items that have different values common to all the bidders. Using a laboratory experiment, we find that, as predicted by theory, it is more beneficial for the seller to sell the higher value item first. We then show that the first-price sealed-bid auction yields higher revenue than the English auction, with significant differences in learning of equilibrium strategies.

Selling shares to budget-constrained bidders: an experimental study of the proportional auction

Selling shares to budget-constrained bidders: an experimental study of the proportional auction

Pacing Equilibrium in First Price Auction Markets

Mature internet advertising platforms offer high-level campaign management tools to help advertisers run their campaigns, often abstracting away the intricacies of how each ad is placed and focusing on aggregate metrics of interest to advertisers. On such platforms, advertisers often participate in auctions through a proxy bidder, so the standard incentive analyses that are common in the literature do not apply directly. In this paper, we take the perspective of a budget management system that surfaces aggregated incentives—instead of individual auctions—and compare first and second price auctions. We show that theory offers surprising endorsement for using a first price auction to sell individual impressions. In particular, first price auctions guarantee uniqueness of the steady-state equilibrium of the budget management system, monotonicity, and other desirable properties, as well as efficient computation through the solution to the well-studied Eisenberg–Gale convex program. Contrary to what one can expect from first price auctions, we show that incentives issues are not a barrier that undermines the system. Using realistic instances generated from data collected at real-world auction platforms, we show that bidders have small regret with respect to their optimal ex post strategy, and they do not have a big incentive to misreport when they can influence equilibria directly by giving inputs strategically. Finally, budget-constrained bidders, who have significant prevalence in real-world platforms, tend to have smaller regrets. Our computations indicate that bidder budgets, pacing multipliers, and regrets all have a positive association in statistical terms. This paper was accepted by Gabriel Weintraub, revenue management and market analytics. Funding: D. Panigrahi was supported in part by the National Science Foundation [Awards CCF 1535972, CCF 1750140, and CCF 1955703]. Supplemental Material: The data files are available at https://doi.org/10.1287/mnsc.2022.4310 .

Uniform Price Auctions with Budget Constrained Bidders: An Experimental Study on Budget Rules

Uniform Price Auctions with Budget Constrained Bidders: An Experimental Study on Budget Rules

Auction Design and Order of Sale with Budget-Constrained Bidders

Auction Design and Order of Sale with Budget-Constrained Bidders

A multi-item auction with budget-constrained bidders and price controls

We extend the multi-item auction model of Talman and Yang (2008) and Andersson et al. (2015) by considering both unit-demand bidders with budget constraints and price controls on bidding items. Due to these budget and price restrictions, a Walrasian equilibrium generally fails to exist. To achieve efficiency, we propose a rationed equilibrium whose allocation is in the core. We also construct an ascending auction to find the proposed rationed equilibrium in (pseudo-)polynomial time.

Mechanisms for combinatorial auctions with budget constraints

This paper studies combinatorial auctions with budget-constrained bidders from a mechanism design perspective. I search for mechanisms that are incentive compatible, individually rational, symmetric, non-wasteful and non-bossy. First focusing on the greedy domain, in which any increase in a bidder’s valuation always exceeds his budget, I derive the unique mechanism, called the Iterative Second Price Auction. For the general domain, however, no such mechanism exists.

Sequential Second Price Auctions with Budget Constrained Bidders

We study an auction game in which two units of a good are sold via two second price auctions sequentially. Bidders value the units identically and have one of two budget levels, high or low. Bidders do not know each others budgets. We show that this game has a unique symmetric equilibrium in which the probabilistic presence of high budget bidders can make bidders bid more aggressively in the first auction, thus lowering prices in the second. As a result if the possibility of competition from high budget bidders is large, then the equilibrium strategies generate declining prices.

Optimally constraining a bidder using a simple budget

I study a principal’s optimal choice of constraint for an agent participating in an auction (or auction-like allocation mechanism). I give necessary and sufficient conditions on the principal’s beliefs about the value of the item for a simple budget constraint to be the optimal contract. The results link the observed use of budget constraints to their use in models incorporating budget-constrained bidders. Other implications of the model are that a general revenue equivalence result applies and that the optimal auction with budget-constrained bidders has a standard solution analogous to the one for classic models.

Mechanisms for Combinatorial Auctions with Budget Constraints

This paper studies combinatorial auctions with budget-constrained bidders from a mechanism design perspective. I search for mechanisms that are incentive compatible, individually rational, symmetric, non-wasteful and non-bossy. First focusing on the greedy domain, in which any increase in a bidder's valuation always exceeds his budget, I derive the unique mechanism, called the Iterative Second Price Auction. For the general domain, however, no such mechanism exists.

Keyword auctions with budget-constrained bidders

We study a keyword auction model where bidders have constrained budgets. In the absence of budget constraints, Edelman et al. (Am Econ Rev 97(1):242–259, 2007) and Varian (Int J Ind Organ 25(6):1163–1178, 2007) analyze “locally envy-free equilibrium” or “symmetric Nash equilibrium” bidding strategies in generalized second-price auctions. However, bidders often have to set their daily budgets when they participate in an auction; once a bidder’s payment reaches his budget, he drops out of the auction. This raises an important strategic issue that has been overlooked in the previous literature: Bidders may change their bids to inflict higher prices on their competitors because under generalized second-price, the per-click price paid by a bidder is the next highest bid. We provide budget thresholds under which equilibria analyzed in Edelman et al. (Am Econ Rev 97(1):242–259, 2007) and Varian (Int J Ind Organ 25(6):1163–1178, 2007) are sustained as “equilibria with budget constraints” in our setting. We then consider a simple environment with one position and two bidders and show that a search engine’s revenue with budget constraints may be larger than its revenue without budget constraints.

A note on the incompatibility of strategy-proofness and Pareto-optimality in quasi-linear settings with public budgets

We show that any deterministic mechanism, for allocating identical items that are complements to budget-constrained bidders, cannot simultaneously satisfy individual-rationality, strategy-proofness, Pareto-efficiency, and no-positive-transfers. This holds even for two bidders, two items, and commonly-known budgets, and generalizes to richer settings.

An Efficient Multi-Item Dynamic Auction with Budget Constrained Bidders

An auctioneer wishes to sell several heterogeneous indivisible items to a group of potential bidders. Each bidder has valuations over the items but faces a budget constraint and may therefore not be able to pay up to his valuations. In such markets, a competitive equilibrium typically fails to exist. We develop a dynamic auction and prove that the auction always finds a core allocation in finitely many rounds. The core allocation consists of an assignment of the items and its associated supporting price vector.

Strong activity rules for iterative combinatorial auctions

Activity rules have emerged in recent years as an important aspect of practical auction design. The role of an activity rule in an iterative auction is to suppress strategic behavior by bidders and promote simple, continual, meaningful bidding and thus, price discovery. These rules find application in the design of iterative combinatorial auctions for real world scenarios, for example in spectrum auctions, in airline landing slot auctions, and in procurement auctions. We introduce the notion of strong activity rules, which allow simple, consistent bidding strategies while precluding all behaviors that cannot be rationalized in this way. We design such a rule for auctions with budget-constrained bidders, i.e., bidders with valuations for resources that are greater than their ability to pay. Such bidders are of practical importance in many market environments, and hindered from bidding in a simple and consistent way by the commonly used revealed-preference activity rule, which is too strong in such an environment. We consider issues of complexity, and provide two useful forms of information feedback to guide bidders in meeting strong activity rules. As a special case, we derive a strong activity rule for non-budget-constrained bidders. The ultimate choice of activity rule must depend, in part, on beliefs about the types of bidders likely to participate in an auction event because one cannot have a rule that is simultaneously strong for both budget-constrained bidders and quasi-linear bidders.

High Bids and Broke Winners

This paper analyzes auctions where budget-constrained bidders have options to declare bankruptcy. It predicts a bidding equilibrium that changes discontinuously in a borrowing rate available to bidders. When the borrowing rate is above a threshold, high-budget bidders win, and the likelihood of bankruptcy is low. When the borrowing rate is below the threshold, the winner is the most budget-constrained bidder and is most likely to declare bankruptcy. This result explains the “high bids and broke winners” anomaly in the C-Block FCC spectrum auction. Based on its equilibrium analysis, the paper proves that a seller can profit from offering to finance the highest bidder at a below-market interest rate, even with default risk. Journal of Economic Literature Classification Numbers: D44, D45, D82, G33, L96.

Multiple-Object Auctions with Budget Constrained Bidders

A seller with two objects faces a group of bidders who are subject to budget constraints. The objects have common values to all bidders but need not be identical, and may be either complements or substitutes. In a simple complete information setting we show: (1) if the objects are sold by means of a sequence of open ascending auctions, then it is always optimal to sell the more valuable object first; (2) the sequential auction yields more revenue than the simultaneous ascending auction used recently by the FCC if the discrepancy in the values is large, or if there are significant complementarities; (3) a hybrid simultaneous-sequential form is revenue superior to the sequential auction; and (4) budget constraints arise endogenously.

Multiple Object Auctions with Budget Constrained Bidders

A seller with two objects faces a group of bidders who are subject to budget constraints. The objects have common values to all bidders, but need not be identical and may be either complements or substitutes. In a simple complete information setting we show: (1) if the objects are sold by means of a sequence of open ascending auctions, then it is always optimal to sell the more valuable object first; (2) the sequential auction yields more revenue than the simultaneous ascending auction used recently by the FCC if the discrepancy in the values is large, or if there are significant complementarities; (3) a hybrid simultaneous-sequential form is revenue superior to the sequential auction; and (4) budget constraints arise endogenously.