Levent Koçkesen

The Strategic Advantage of Negatively Interdependent Preferences

We study certain classes of supermodular and submodular games which are symmetric with respect to material payoffs but in which not all players seek to maximize their material payoofs. Specially, a subset of players have negatively interdependent preferences and care not only about their own material payoffs but also about their payoffs relative to others. We identify sufficient conditions under which members of the latter group have a strategic advantage in the following sense: at all intragroup symmetric equilibria of the game, they earn strictly higher material payoffs than do players who seek to maximize their material payoffs.

Evolution of interdependent preferences in aggregative games

We study the evolution of preference interdependence in aggregative games which are symmetric with respect to material payoffs but asymmetric with respect to player objective functions. Specifically, some players have interdependent preferences (in the sense that they care not only about their own material payoffs but also about their payoffs relative to others) while the remainder are (material) payoff maximizers in the standard sense.

Strategic Delegation by Unobservable Incentive Contracts

Many strategic interactions in the real world take place among delegates empowered to act on behalf of others. Although there may be a multitude of reasons why delegation arises in reality, one intriguing possibility is that it yields a strategic advantage to the delegating party. In the case where only one party has the option to delegate, we analyze the possibility that strategic delegation arises as an equilibrium outcome under completely unobservable incentive contracts within the class of two-person extensive form games. We show that delegation may arise solely due to strategic reasons in quite general economic environments even under unobservable contracts. Furthermore, under some reasonable restrictions on out-of-equilibrium beliefs and actions of the outside party, strategic delegation is shown to be the only equilibrium outcome.

Negatively interdependent preferences

Abstract. We develop a theory of representation of interdependent preferences that reflect the widely acknowledged phenomenon of keeping up with the Joneses (i.e. of those preferences which maintain that well-being depend on “relative standing” in the society as well as on material consumption). The principal ingredient of our analysis is the assumption that individuals desire to occupy a (subjectively) better position than their peers. This is quite a primitive starting point in that it does not give any reference to what is actually regarded as “status” in the society. We call this basic postulate negative interdependence, and study its implications. In particular, combining this assumption with some other basic postulates that are widely used in a number of other branches of the theory of individual choice, we axiomatize the relative income hypothesis, and obtain an operational representation of interdependent preferences.

Popular support for progressive taxation and the relative income hypothesis

Abstract We show that a marginal rate progressive tax always defeats a marginal rate regressive tax under pairwise majority voting (so long as the latter collects at least as much revenue as the former one) irrespective of whether the voters care at all about their relative incomes or not.

Strategic Effects of Renegotiation-Proof Contracts

Abstract It is well known that non-renegotiable contracts with third parties may have an effect on the outcome of a strategic interaction and thus serve as a commitment device. We address this issue when contracts are renegotiable. More precisely, we analyze the equilibrium outcomes of two-stage games with renegotiation-proof third-party contracts in relation to the equilibrium outcomes of the same game without contracts. We assume that one of the parties in the contractual relationship is unable to observe everything that happens in the game when played by the other party. We first show that when contracts are non-renegotiable, the set of equilibrium outcomes of the game with contracts is restricted to a subset of Nash equilibrium outcomes of the original game. Introducing renegotiation, in general, imposes further constraints and in some games implies that only subgame perfect equilibrium outcomes of the original game can be supported. However, there is a large class of games in which non-subgame perfect equilibrium outcomes can also be supported, and hence, third-party contracts still have strategic implications even when they are renegotiable.

Strategic Effects of Incomplete and Renegotiation-Proof Contracts

It is well known that non-renegotiable contracts with third parties may have an effect on the outcome of a strategic interaction and thus serve as a commitment device. We address this issue when contracts are renegotiable. More precisely, we analyze the equilibrium outcomes of twostage games with renegotiation-proof third-party contracts in relation to the equilibrium outcomes of the same game without contracts. We assume that one of the parties in the contractual relationship is unable to observe everything that happens in the game when played by the other party. This implies that contracts are incomplete and we show that such incompleteness restricts the set of equilibrium outcomes to a subset of Nash equilibrium outcomes of the game without contracts. Introducing renegotiation, in general, imposes further constraints and in some games implies that only subgame perfect equilibrium outcomes can be supported. However, there is a large class of games in which non-subgame perfect equilibrium outcomes can also be supported, and hence, third-partycontracts still have strategic implications even when they are renegotiable.

The role of verifiability and privacy in the strategic provision of performance feedback: Theory and experimental evidence

We theoretically and experimentally analyze the role of verifiability and privacy in strategic performance feedback using a “one principal-two agent” context with real effort. We confirm the theoretical prediction that information transmission occurs only in verifiable feedback mechanisms and private-verifiable feedback is the most informative mechanism. Yet, subjects also exhibit some behavior that cannot be explained by our baseline model, such as telling the truth even when this will definitely hurt them, interpreting “no feedback” more optimistically than they should, and being influenced by feedback given to the other agent. We show that a model with individual-specific lying costs and naive agents can account for some, but not all, of these findings. We conclude that in addition to being naive, some agents also suffer from self-serving biases and engage in non-Bayesian social comparisons in their interpretation of performance feedback.

Delegation with Incomplete and Renegotiable Contracts

It is well known that delegating the play of a game to an agent via incentive contractsmay serveas a commitment device and hence provide a strategic advantage. Previous literature has shown that any Nash equilibrium outcome of an extensive-form principals-only game can be supported as a sequential equilibrium outcome of the induced delegation game when contracts are unobservable and non-renegotiable. In this paper we characterize equilibriumoutcomes of delegation games with unobservable and incomplete contractswith andwithout renegotiation opportunities under the assumption that the principal cannot observe every history in the game when played by her agent. We show that incompleteness of the contracts restricts the set of outcomes to a subset of Nash equilibrium outcomes and renegotiation imposes further constraints. Yet, there is a large class of games in which non-subgame perfect equilibrium outcomes of the principals-only game can be supported even with renegotiable contracts, and hence delegation still has a bite.