In this paper, an infinitely-repeated Bertrand game is considered. The model has a two-tier relationship; two firms make a self-enforced collusive agreement and each firm writes a law-enforced contract to its privately-informed agent. The main finding is that in optimal collusion, interaction between intra-firm (internal) contracting and inter-firm collusion may be exploited; inter-firm collusi...

We present a secure routing protocol that is immune to Sybil attacks and that can tolerate collusion of Byzantine routers. It can tolerate either initial collusion of Byzantine routers or runtime collusion of non-adjacent Byzantine routers, both in the absence of runtime collusion between adjacent routers. For these settings, the calculated distance from a destination to a node is not smaller t...

Reputation fraud is prevalent in online social networks. Numerous services provide fake content, likes, and followers to artificially boost the popularity and trustworthiness of brands and celebrities. Such activities undermine the trusted nature of online social networks. In this paper, we uncover a thriving ecosystem of reputation manipulation services on Facebook that leverage the principle ...

In content fingerprinting, the same media covertext—image, video, audio, or text—is distributed to many users. A fingerprint, a mark unique to each user, is embedded into each copy of the distributed covertext. In a collusion attack, two or more users may combine their copies in an attempt to “remove” their fingerprints and forge a pirated copy. To trace the forgery back to members of the coali...

In collusion-free protocols, subliminal communication is impossible and parties are thus unable to communicate any information “beyond what the protocol allows.” Collusion-free protocols are interesting for several reasons, but have specifically attracted attention because they can be used to reduce trust in game-theoretic mechanisms. Collusion-free protocols are impossible to achieve (in gener...

In this paper, we ask whether courts should continue to rule settlements in the context of pharmaceutical claims per se legal, when these settlements comprise payments from originator to generic companies, potentially delaying generic entry compared to the underlying litigation. Within a theoretical framework we compare consumer welfare under the rule of per se legality with that under alternat...

In the context of cooperative games with transferable utility, an inclusive collusion grants each colluding player access to resources of all colluding players and therefore transforms a given game. Inclusive collusion neutrality requires that no group of players can change their total payo↵ with an inclusive collusion. Assuming that collusion formation is governed by a network defined over pla...

This chapter is to explain the China Model characterized with “high economic growth rate concomitant with high frequency of vicious accidents” by constructing a formal model of the local government–firm collusion. Section 2.1 introduces three famous or infamous events about PX (p-Xylene) projects in China and raises two questions relevant to these events. Section 2.2 makes a literature review o...

We analyze collusion in two comparable market structures. In the first market structure only one firm is vertically integrated; there is one more independent firm in the upstream industry and another independent firm in the downstream industry. In the second market structure, there are only two vertically integrated firms that can trade among themselves in the intermediate good market. The seco...

We investigate regulation as the outcome of a bargaining process between a regulator and a regulated firm. The regulator is required to monitor the firm’s costs and reveal its information to a political principal (Congress). In this setting, we explore the scope for collusion between the regulator and the firm, which results in the manipulation of the regulator’s report on the firm’s costs to C...