Experimental methods are used to examine the existence and detectability of collusion in environments that exhibit critical parallels to procurement auctions. We find that, given the opportunity, sellers often raise prices considerably. Moreover, non-collusive Nash equilibrium predictions are insufficient to dismiss “suspicious” behavior as innocuous: In an environment where identical prices ar...

This study qualitatively examined the perspectives of clinical social workers on non-offending mothers of sexually abused children. The study examined whether clinicians still used collusion to explain mothers' behavior, despite research refuting collusion. Findings revealed that, although workers did not use collusion, they still constructed mothers negatively. Multiple contexts of agency prac...

In this note we take a first step towards the analysis of collusion in markets with spatial competition, focusing on the case of pure location choices. We find that collusion can only be profitable if a coalition contains more than half of all players. This result holds for location games played in k-dimensional Euclidean space as long as consumers are distributed via atomless density functions...

Dominant-strategy truthfulness is traditionally considered the best possible solution concept in mechanism design, as it enables one to predict with confidence which strategies independent players will actually choose. Yet, as with any other form of equilibrium, it too can be extremely vulnerable to collusion. The problem of collusion is particularly evident for unrestricted combinatorial aucti...

Digital fingerprints are unique labels inserted in different copies of the same content before distribution. Each digital fingerprint is assigned to an intended recipient, and can be used to trace the culprits who use their content for unintended purposes. Attacks mounted by multiple users, known as collusion attacks, provide a cost-effective method for attenuating the identifying fingerprint f...

The paper considers tacit collusion in markets which are not fully transparent on both sides. Consumers only detect prices with some probability before deciding which …rm to purchase from, and each …rm only detects the other …rm’s price with some probability. Increasing transparency on the producer side facilitates collusion, while it increasing transparency on the consumer side makes collusion...

Collusion-free protocols prevent subliminal communication (i.e., covert channels) betweenparties running the protocol. In the standard communication model (and assuming the existenceof one-way functions), protocols satisfying any reasonable degree of privacy cannot be collusion-free. To circumvent this impossibility result, Alwen et al. recently suggested the mediatedmodel where...