Collusion In Auctions Research Articles

Collusion in Auctions with Constrained Bids: Theory and Evidence from Public Procurement

We study the mechanics of cartel enforcement and its interaction with bidding constraints in the context of repeated procurement auctions. Under collusion, bidding constraints weaken cartels by limiting the scope of punishment. This yields a test of collusive behavior exploiting the counterintuitive prediction that introducing minimum prices can lower the winning-bid distribution. The model’s predictions are borne out in Japanese procurement data, where we find evidence that minimum prices weakened collusion. A robust design insight is that setting a minimum price at the bottom of the observed winning-bid distribution necessarily improves over a minimum price of zero.

Collusion and signaling in auctions with interdependent values

The standard approach to collusion in auctions posits an uninformed, disinterested third party who, prior to the auction, designs and implements a collusive mechanism. In environments where collusion agreements are likely to be both proposed and executed by the involved parties, this approach may neglect information leakages from simply a proposal to collude. We consider a model of collusion where one informed bidder proposes to another, as in Eső and Schummer (2004). We allow for general interdependent values and affiliated signals. In contrast to third party modeling approaches, collusion is inefficient from both a social perspective (except for the case of pure common values) and from the perspective of the ring. Both bidders are better off than without colluding, but the surplus extracted from the seller is distributed asymmetrically between the bidders. The potential for information leakage from proposing is bad for low types, who reveal that they are weak competitors, but is advantageous for high types, because they are able to signal their strength. We identify a so-called “briber's curse,” whereby acceptance of a proposal causes the proposer to downgrade her expected value for the object. When there is additional competition in the form of bidders outside of the cartel, the briber's curse significantly harms cartel profits and raises seller revenues.

Collusion and information revelation in auctions

The theoretical literature on collusion in auctions suggests that the first-price mechanism can deter the formation of bidding rings. However, such analyses neglect to consider the effects of failed collusion attempts, wherein information revealed in the negotiation process may affect bidding behaviour. We experimentally test a setup in which theory predicts no collusion and no information revelation in first-price auctions. The results reveal a hitherto overlooked failing of the first-price mechanism: failed collusion attempts distort bidding behaviour, resulting in a loss of seller revenue and efficiency. Moreover, the first-price mechanism does not result in less collusion than the second-price mechanism. We conclude that, while the features of the first-price mechanism may have the potential to deter bidder collusion, the role of beliefs in guiding bidding behaviour make it highly susceptible to distortions arising from the informational properties of collusive negotiation. Auction designers should take this phenomenon into account when choosing the auction mechanism.

Auction Mechanisms and Bidder Collusion: Bribes, Signals and Selection

The theoretical literature on collusion in auctions suggests that the first-price mechanism can deter the formation of bidding rings. In equilibrium, collusive negotiations are either successful or are avoided altogether, hence such analysis neglects the effects of failed collusion attempts. In such contingencies, information revealed in the negotiation process is likely to affect the bidding behavior in firstprice (but not second-price) auctions. We test experimentally a setup in which collusion is possible, but negotiations often break down and information is revealed in an asymmetric way. The existing theoretical analysis of our setup predicts that the first-price mechanism deters collusion. In contrast, we find the same level of collusion in first-price and second-price auctions. Furthermore, failed collusion attempts distort the bidding behavior in the ensuing auction, leading to loss of efficiency and eliminating the revenue dominance typically observed in first-price auctions.

Collusion in Auctions with Constrained Bids: Theory and Evidence from Public Procurement

Collusion in Auctions with Constrained Bids: Theory and Evidence from Public Procurement

Optimal Ring Size at First-Price Auctions

This paper studies the optimal-ring-size problem in a first-price auction environment, where a collusive ring center can endogenously choose the number of its members. The key finding is that, contrary to the results for second-price auctions, the optimal ring at first-price auctions is generally not all-inclusive, especially when the number of bidders is large. Outsiders can free-ride the ring's suppressed competition and earn higher payoffs than by being a ring member; hence they choose not to participate in collusion. As a partial ring creates bidder asymmetry at first-price auctions, the overall allocation will be inefficient, which provides a basis for laws that outlaw collusion in auctions.

The Cascade Auction — A Mechanism for Deterring Collusion in Auctions

We introduce a sealed bid auction of a single item in which the winner is chosen at random among the highest k bidders according to a fixed probability distribution, and the price for the chosen winner is the Vickrey-Clarke-Groves price. We call such an auction a cascade auction. Our analysis suggests that this type of auction may give higher revenues compared to second price auction in cases of collusion.

MULTIUNIT AUCTIONS

AbstractWe survey experimental research on multiunit auctions with an emphasis on topics that may be of a unifying interest to experimental, as well as theoretical and empirical economists. Topics include static and dynamic multiunit auctions; combinatorial auctions and efficient auction design; simultaneous and sequential auctions; bidder asymmetry and endogenous entry, and collusion in auctions. We also discuss behavioral regularities observed in multiunit auction experiments.

Strategic collusion in auctions with externalities

We study a first price auction preceded by a negotiation stage, during which bidders may form a bidding ring. We prove that in the absence of external effects the all-inclusive ring forms in equilibrium, allowing ring members to gain the auctioned object for a minimal price. However, identity dependent externalities may lead to the formation of small rings, as often observed in practice. Potential ring members may condition their participation on high transfer payments, as a compensation for their expected (negative) externalities if the ring forms. The others may therefore profitably exclude such demanding bidders, although risking tougher competition in the auction. We also analyze ring inefficiency in the presence of externalities, showing that a ring may prefer sending an inefficient member to the auction, if the efficient member exerts threatening externalities on bidders outside the ring, which in turn leads to a higher winning price.

Estimating Revenue under Collusion-Proof Auctions

Collusion in auctions affects both revenue and efficiency and are prevalent. Yet, sellers do not use collusion-proof auctions as often as they should. Why is that? We find that one reason for this could be the cost of implementing efficient collusion-proof auctions. We use California highway procurements data, to estimate the cost of implementing collusion-proof auction. Our estimates show that cost must increase by at least 10.8% to ensure efficient outcome. The cost can sometimes be as high as 48.8% (depending on the size of bidding-ring in the data).

Breaking Collusion in Auctions through Speculation: An Experiment on CO2 Emission Permit Markets

AbstractThe European Emission Trading Scheme (EU‐ETS) has chosen to adopt an auctioning procedure to initially allocate CO2 emission permits. Free allocation of permits will become an exception for the third phase (2013–2020) and most firms will have to buy all their permits on the market or via auctions. The ability of bidders to collude is a key concern about the design of the auction format. To counter collusion, the auction can be open to bidders without compliance obligations (speculators). This paper aims at studying experimentally speculation as a collusion‐breaking device in two different auction mechanisms: the uniform‐price sealed‐bid auction and the ascending clock auction. Our results suggest that a uniform sealed‐bid auction open to speculators should be chosen from a revenue maximization point of view. In this mechanism, compliance agents adopt an aggressive strategy toward speculators. This strategy significantly increases the seller's revenue, compared to the more collusive clock auction. In the latter, on the contrary, bidders accommodate speculators, letting them buy permits in the auction and buying their necessary permits on the secondary market. However, as opening the auction to speculators deteriorates efficiency, the regulator faces a trade‐off between these two objectives.

Detection of collusion in government procurement auctions

Research on bidder collusion in procurement auctions is reasonably successful in unveiling the mechanisms of collusion among the bidders. But it is relatively weak in forwarding effective practical methods of collusion detection before the winner is declared, because they presuppose the knowledge of collusion in specific auctions. Past studies, however, point out the need for working with bid price-to-reserve price ratios rather than bid prices or winning bid prices, to be free from the problem of heteroscedasticity. They also draw an important inference that the set of collusive data are significantly different from the set of competitive data. On the basis of these basic facts, the current paper outlines a seven-step approach to collusion detection. The approach makes rudimentary statistical analysis of bid price-to-reserve price ratios for all the bidders. The analysis comprises tests of equality of means, medians and variance and tests of skewness, autocorrelation and normality of the ratios. It divides the ratios into two significantly different clusters. The cluster with the higher mean and variance values of the ratios corresponds to collusive bidding with the other cluster corresponding to competitive bidding. The paper proposes the construction of a process control chart to detect occurrence of collusion in an auction immediately after the price bids are opened. The approach is illustrated by applying it to data from procurement auctions for construction projects in a State Department of the Republic of India.

A cooperative approach to collusion in auctions

The elegant Vickrey Clarke Groves (VCG) mechanism is well-known for the strong properties it offers: dominant truth-revealing strategies, efficiency and weak budget-balance in quite general settings. Despite this, it suffers from several drawbacks, prominently susceptibility to collusion. By jointly setting their bids, colluders may increase their utility by achieving lower prices for their items. The colluders can use monetary transfers to share this utility, but they must reach an agreement regarding their actions. We analyze the agreements that are likely to arise through a cooperative game theoretic approach, transforming the auction setting into a cooperative game. We examine both the setting of a multi-unit auction as well as path procurement auctions.

Core-stable rings in auctions with independent private values

We propose a semi-cooperative game theoretic approach to check whether a given coalition is stable in a Bayesian game with independent private values. The ex ante expected utilities of coalitions, at an incentive compatible (noncooperative) coalitional equilibrium, describe a (cooperative) partition form game. A coalition is core-stable if the core of a suitable characteristic function, derived from the partition form game, is not empty. As an application, we study collusion in auctions in which the biddersʼ final utility possibly depends on the winnerʼs identity. We show that such direct externalities offer a possible explanation for cartelsʼ structures (not) observed in practice.

Core-Stable Rings in Auctions with Independent Private Values

We propose a semi-cooperative game theoretic approach to check whether a given coalition is stable in a Bayesian game with independent private values. The ex ante expected utilities of coalitions, at an incentive compatible (noncooperative) coalitional equilibrium, describe a (cooperative) partition form game. A coalition is core-stable if the core of a suitable characteristic function, derived from the partition form game, is not empty. As an application, we study collusion in auctions in which the bidders’ final utility possibly depends on the winner’s identity. We show that such direct externalities offer a possible explanation for cartels’ structures (not) observed in practice.

Collusion in auctions for emission permits: An experimental analysis

AbstractEnvironmental markets have several institutional features that provide a new context for the use of auctions and that have not been studied previously. This paper reports on laboratory experiments testing three auction forms—uniform and discriminatory price sealed‐bid auctions and an ascending clock auction. We test the ability of subjects to tacitly or explicitly collude in order to maximize profits. Our main result is that the discriminatory and uniform price auctions produce greater revenues than the clock auction, both with and without explicit communication. The clock appears to facilitate successful collusion, both because of its sequential structure and because it allows bidders to focus on one dimension of cooperation (quantity) rather than two (price and quantity).© 2009 by the Association for Public Policy Analysis and Management.

Fighting collusion in auctions: An experimental investigation

The danger of collusion presents a serious challenge for auctioneers. In this paper, we compare the collusive properties of two standard auctions, the English auction and the first-price sealed-bid auction, and a lesser-known format, the Amsterdam (second-price) auction. In the Amsterdam auction, the highest losing bidder earns a premium for stirring up the price. We study two settings: in one, all bidders can collude, and in another, only a subset is eligible. The experiments show that the Amsterdam auction triggers less collusion than the standard auctions. We compare experimental results to theoretical predictions, and provide an explanation where they differ.

Collusion in Auctions for Emission Permits: An Experimental Analysis

Environmental markets have several institutional features that provide a new context for the use of auctions and which have not been studied previously. This paper reports on laboratory experiments testing three auction forms: uniform and discriminatory price sealed bid auctions and an ascending clock auction. We test the ability of subjects to tacitly or explicitly collude in order to maximize profits. Our main result is that the discriminatory and uniform price auctions produce greater revenues than the clock auction, both without and with explicit communication. The clock appears to be more subject to successful collusion because of its sequential structure and because it allows bidders to focus on one dimension of cooperation (quantity) rather than two (price and quantity).

USING THE SPATIAL DISTRIBUTION OF BIDDERS TO DETECT COLLUSION IN THE MARKETPLACE: EVIDENCE FROM TIMBER AUCTIONS*

ABSTRACT This study develops identification strategies utilizing spatial bidding patterns to detect possible collusion in auction markets. The identification strategy is applied to examine bidder behavior using data drawn from nearly 3,000 auctions (over 10,000 individual bids) for cutting rights of standing timber in British Columbia for the period 1996–2000. Results suggest that observed patterns of behavior are inconsistent with a model of perfectly competitive bidding. Further, changes in such patterns across geographic space are remarkably consistent with patterns of decay in the transmission of knowledge reported in previous empirical work on spillovers.

Modeling Tacit Collusion in Auctions

We study tacit collusion, which we interpret as collusion without communication about strategies, in repeated auctions in which bidders can only observe past winners and not their bids. Strategies cannot discriminate among initially nameless bidders until they have become named through winning an auction. We obtain two classes of results: (1) Completely refraining from using names rules out collusion altogether, and even if naming is permitted, as per our definition of tacit collusion, the lack of communication limits collusive strategies and payoffs among impatient bidders. (2) Sufficiently patient bidders can overcome the attainability constraints imposed by lack of communication and obtain approximately the same collusive gain as absent communication.