Dynamic common agency

A general model of dynamic common agency with symmetric information is considered. The set of truthful Markov perfect equilibrium payoffs is characterized and the efficiency properties of the equilibria are established. A condition for the uniqueness of equilibrium payoffs is derived for the static and the dynamic game. The payoff is unique if and only if the payoff of each principal coincides with his marginal contribution to the social value of the game. The dynamic model is applied to a game of agenda setting.     

Selecting equilibria in common agency games

We characterize equilibrium payoffs of a delegated common agency game in a public good context where principals use smooth contribution schedules. We prove that under complete information, payoff vectors of equilibria with truthful schedules coincide with the set of smooth equilibrium payoffs, including non-truthful schedules. We next consider whether the presence of arbitrarily small amounts of asymmetric information is enough to refine this payoff set. Providing that the extensions of the equilibrium schedules beyond the equilibrium point are flatter than truthful schedules, the set of equilibrium payoffs is strictly smaller than the set of smooth (equivalently, truthful) equilibrium payoffs. Interestingly, some forms of asymmetric information do not sufficiently constrain the slopes of the extensions and fail to refine the payoff set. In the case of a uniform distribution of types and arbitrary out-of-equilibrium contributions, the refinement has no bite. If, however, one restricts out-of-equilibrium behavior in a natural way, the refinement is effective. Alternatively, we may consider an exponential distribution with unbounded support (and hence no out-of-equilibrium choices) and we find that the refinement selects a unique equilibrium payoff vector equal to Lindahl prices.As a separate contribution, equilibria with forcing contracts are also considered both under complete and asymmetric information.     

From private to public common agency

This note establishes that two propositions in the theory of private common agency by Laussel and Le Breton (J. Econ. Theory 100 (2001) 93) extend to a larger class of games, in which each principal's gross monetary payoff does not depend exclusively on the quantities she receives. A new result is offered to demonstrate that Proposition 4.3 is robust to the introduction of negative externalities. An existing result is reinterpreted to show that Proposition 4.2 is robust to the introduction of positive externalities.     

Negotiation and take it or leave it in common agency

This paper contrasts models of common agency in which principals compete in incentive contracts (that is, they make take it or leave it offers) with models where principals offer agents menus of incentive contracts from which the final contract is negotiated. It is shown that pure strategy equilibria in incentive contracts are robust to the possibility that principals might offer menus. In addition, a no-externalities condition is given such that any pure strategy equilibrium allocation with menus can be supported with competition in incentive contracts. The no-externalities condition is restrictive, but it is shown that it applies in most well-known common agency problems, including, for example, the Bertrand pricing problem.     

Negotiation and take-it or leave-it in common agency with non-contractible actions

In a recent paper, Peters [Negotiation and take-it or leave-it in common agency, J. Econ. Theory 111 (2003) 189-228] identifies a set of restrictions on players’ preferences, called “no-externalities assumption”, under which, in common agency games, there is no loss of generality in restricting principals’ strategies to be take-it or leave-it offers. The present note provides an example to show that these conditions are not sufficient when the agent takes a non-contractible action.     

Existence of equilibrium in common agency games with adverse selection

We establish the existence of subgame perfect equilibria in general menu games, known to be sufficient to analyze common agency problems. Our main result states that every menu game satisfying enough continuity properties has a subgame perfect equilibrium. Despite the continuity assumptions that we make, discontinuities naturally arise due to the absence, in general, of continuous optimal choices for the agent. Our approach, then, is based on (and generalizes) the existence theorem of [Simon, L., Zame, W., 1990. Discontinuous games and endogenous sharing rules. Econometrica 58 (4), 861–872] designed for discontinuous games.     

Representing equilibrium aggregates in aggregate games with applications to common agency

An aggregate game is a normal-form game with the property that each playerʼs payoff is a function of only his own strategy and an aggregate of the strategy profile of all players. Such games possess properties that can often yield simple characterizations of equilibrium aggregates without requiring that one solves for the equilibrium strategy profile. When payoffs have a quasi-linear structure and a degree of symmetry, we construct a self-generating maximization program over the space of aggregates with the property that the solution set corresponds to the set of equilibrium aggregates of the original n-player game. We illustrate the value of this approach in common-agency games where the playersʼ strategy space is an infinite-dimensional space of nonlinear contracts. We derive equilibrium existence and characterization theorems for both the adverse selection and moral hazard versions of these games.     

An Optimal Auction for Complements

This paper considers the optimal selling mechanism for complementary items. When buyers are perfectly symmetric, the optimal procedure is to bundle the items and run a standard auction. In general, however, bundling the items is not necessarily desirable, and the standard auctions do not maximize revenue. Moreover, the optimal auction allocation may not be socially efficient since the auction must discriminate against bidders who have strong incentives to misrepresent their true preferences.Journal of Economic LiteratureClassification Number: D44.     

Cooperation in Experimental Games of Strategic Complements and Substitutes

We conduct a laboratory experiment aimed at examining whether strategic substitutability and strategic complementarity have an impact on the tendency to cooperate in finitely repeated two-player games with a Pareto-inefficient Nash equilibrium. We find that there is significantly more cooperation when actions exhibit strategic complementarities than in the case of strategic substitutes. The difference is to some extent driven by a difference in the speed with which some pairs reach stable full cooperation, but mainly by differences in choices of pairs that do not succeed in reaching full cooperation.     

Complements, Substitutes, Budget Constraints and Valuation

This study employs a multi-program contingent valuation (CVM) design tosimultaneously assess the value of three ecosystem conservation programsin Alberta, Canada. The design is different from most other CVM designsand has several different features including the natural incorporation ofdirect reminders of substitute/complementary programs and budgetconstraints. In contrast to the findings of other studies, two of the environmentalprograms appear to be complements and other combinations of the programssuggest an absence of substitution effects. The multi-program model ismore informative and robust in terms of theoretical validity and expectedrelationships with demographic and recreational characteristics of therespondents.     

Haggling over substitutes

Using a model of substitutable goods I determine generic conditions on tastes which guarantee that fixed prices are not optimal: the fully optimal tariff includes lotteries. That is, a profit maximising seller would employ a haggling strategy. We show that the fully optimal selling strategy in a class of cases requires a seller to not allow themselves to focus on one good but to remain haggling over more than one good. This throws new light on the selling strategies used in diverse industries. These insights are used to provide a counter-example to the no lotteries result of McAfee and McMillan (J. Econ. Theory 46 (1988) 335).     

Gross substitutes and immiserizing growth

In a pure exchange economy immiserizing growth occurs when an increase in the endowment of one trader results in a new equilibrium where that trader has lower utility. This paper demonstrates that such perverse behavior is ruled out when excess demands satisfy a particular gross substitute condition.     

Combinatorial agency

We study a combinatorial variant of the classical principal-agent model. In our setting a principal wishes to incentivize a team of strategic agents to exert costly effort on his behalf. Agents? actions are hidden and the principal observes only the outcome of the team, which depends stochastically on the complex combinations of the efforts by the agents. The principal seeks the mechanism that maximizes the principal?s net revenue given an equilibrium behavior of the agents. We investigate the structure of the optimal mechanism for various production technologies as the principal?s value from the project varies. In doing so we quantify the gap between the first-best and second-best solutions. Our results highlight the qualitative and quantitative differences between production technologies that exhibit complementarities and substitutabilities between the agents? actions. In comparing the first best with the second best we highlight the role of effort monitoring by the principal. As we shall see, the benefit from monitoring crucially depends on the underlying technology, with the two polar cases being perfect substitution and perfect complementarity.     

Capital Maintenance and Investment: Complements or Substitutes?

This paper studies the properties of demand for capital maintenance services and its interaction with investment under variable capital utilization rate and adjustment costs. The depreciation rate varies with the maintenance effort and the utilization rate of capital. We show that the properties of the demand functions for maintenance services and capital goods depend closely on the sign of the cross derivative of the depreciation function, i.e., on whether the marginal efficiency of maintenance decreases or increases when the rate of capital utilization rises. In our model, it is impossible to reconcile some unquestionable empirical facts and some minimal regularity conditions on the demand function for maintenance services if this cross derivative is positive. In all cases, investment and maintenance are gross complements. Received September 9, 2001; revised version received April 22, 2002 Published online: December 5, 2002 ? Springer-Verlag 2002     

Competition and corruption in an agency relationship

The paper reconsiders the relationship between competition and corruption in a model, where corruption has solid informational foundations and where the regulatory response to the possibility of corruption is taken into account. It is shown that the effect of greater competition on corruption depends on the complementarity or substitutability of the two instruments available to decrease information rents, namely low powered incentives and greater competition. The paper concludes with a brief empirical exploration of the relationship between competitiveness and corruption on African data.     

Contract renegotiation and options in agency problems

This article discusses the ability of an agent and a principalto achieve the first-best outcome when the agent invests inan asset that has greater value if owned by the principal thanby the agent. When contracts can be renegotiated, a well-knowndanger is that the principal can hold up the agent, underminingthe agent's investment incentives. We begin by identifying acountervailing effect: Investment by the agent can increasehis value for the asset, thus improving his bargaining positionin renegotiation. We show that option contracts will achievethe first best whenever his threat-point effect dominates theholdup effect. Otherwise, achieving the first best is difficultand, in many cases, impossible.     

Wealth effects and agency costs

We analyze how the agent's initial wealth affects the principal's expected profits in the standard principal–agent model with moral hazard.We show that if the principal prefers a poorer agent for all specifications of action sets, probability distributions, and disutility of effort, then the agent's utility of income must exhibit a coefficient of absolute prudence less than three times the coefficient of absolute risk aversion for all levels of income, thus strengthening the sufficiency result of Thiele and Wambach (1999). Also, we prove that there is no condition on the agent's utility of income alone that will make the principal prefer richer agents. Moreover, we show that, for an interesting class of problems, the principal prefers a relatively poorer agent if agent's wealth is sufficiently large. Finally, we discuss how alternative ways of modeling the agent's outside option affects the principal's preferences for agent's wealth.     

Renegotiation-proof contract in repeated agency

Renegotiation-proof contracts are studied in infinitely repeated principal–agent problem. Contracts satisfying a weaker notion of renegotiation-proofness always exist. The renegotiation-proof value function has a simple characterization: It is the principal's optimal value function when an appropriate lower bound is placed on the agent's expected utility. Sufficient conditions are provided for renegotiation-proof value function in finite horizon to converge to renegotiation-proof value function in infinite horizon as time goes to infinity.