Adverse selection problems without the Spence-Mirrlees condition

This paper studies a class of one-dimensional screening problems where the agent's utility function does not satisfy the Spence-Mirrlees condition (SMC). The strength of the SMC for hidden information problems is to provide a full characterization of implementable contracts using only the local incentive compatibility (IC) constraints. These constraints are equivalent to the monotonicity of the decision variable with respect to the agent's unobservable one-dimensional parameter. When the SMC is violated the local IC constraints are no longer sufficient for implementability and additional (global) IC constraints have to be taken into account. In particular, implementable decisions may not be monotonic and discretely pooled types must have the same marginal utility of the decision (or equivalently, get the same marginal tariff). Moreover, at the optimal decision, the principal must preserve the same trade-off between rent extraction and allocative distortion measured in the agent's marginal rent unit. In a specific setting where non-monotone contracts may be optimal we fully characterize the solution.     

Double Moral Hazard,Monitoring, and the Nature of Contracts

generalized double-sided moral-hazard model, with risk-averse parties who mutually monitor each other (to get a reasonable idea of outcome/effort). The model considers trade-off between monitoring costs and moral hazard costs, which are endogenously determined by the extent of monitoring. Using this model, we formally prove a generalized version of Coase's conjecture – that the optimal contract minimizes the agency and risk costs. We then show how varying assumptions about the feasibility or cost of monitoring of the outcome or the worker's effort lead to different contracts being optimal. The analysis is then used to explain the nature of contracts observed in practice under many different situations. We will give an explanation as to why industrial workers typically work under wage contracts, while share contracts are common in agriculture and will explain why profit sharing is more common for senior managers than for the production workers. Received September 19, 2000; revised version received October 30, 1997     

Dynamic labor contracts with temporary layoffs and permanent separations

Summary. We study the implications of optimal dynamic contracts in private information environments for fluctuations in effort and employment across time and productivity states. To this end, we incorporate temporary layoffs and permanent separations as well as on-the-job effort variations into a dynamic model of moral hazard. We consider two different “commitment” environments. In a “full commitment” environment, although the firm can temporarily lay a worker off, neither party can dissolve the contractual relationship once it has been initiated. On the other hand, in a “limited commitment” environment, both parties can dissolve the relationship at the beginning of any period in order to pursue an outside option. We use our model to study the implications of optimal contracts for incentives, employment histories, layoffs and separations across full information, full commitment and limited commitment settings. We compute solutions to the relevant principal-agent problems, endogenously determining the set of states in which separations occur and the domain of the firm's value function, as well as the value function itself. Received: February 28, 2000; revised version: January 21, 2001     

ON EMPLOYMENT CONTRACTS WITH ENDOGENOUS ON-THE-JOB SEARCH

We consider an equilibrium search model and employment contracts when workers have endogenous on-the-job search. When a firm tries to retain an employee by matching outside offers, variable search intensity leads to a moral hazard problem. We first consider workers with identical productivities. We derive an equilibrium where firms commit not to respond to outside offers and workers search less. Second, we investigate the case with heterogeneous workers and asymmetric information. Assuming that firms can commit to retain all workers irrespective of their ability, we establish conditions under which it is optimal to do so. This policy again reduces the incentive for active on-the-job search. We discuss an equilibrium where all firms use these so-called ‘pooling’ contracts.     

Contracts without memory in multiperiod agency models

Settings are considered in which optimal multiperiod contracts can have no memory, i.e., where second period payments do not need to depend on first period outcomes. If contracts have no memory, a repeated agency game can be played myopically; there are no gains to long-term relationships. Conditions on preferences for a no memory contract are presented. In an agency game with moral hazard on the act selection, preference separability and domain additivity imply the existence of a no memory contract. In a setting without moral hazard but with asymmetric information on the outcome, domain additivity implies no memory.     

Dynamic contracting with persistent shocks

In this paper, we develop continuous-time methods for solving dynamic principal-agent problems in which the agent's privately observed productivity shocks are persistent over time. We characterize the optimal contract as the solution to a system of ordinary differential equations and show that, under this contract, the agent's utility converges to its lower bound—immiserization occurs. Unlike under risk-neutrality, the wedge between the marginal rate of transformation and a low-productivity agent's marginal rate of substitution between consumption and leisure will not vanish permanently at her first high-productivity report; also, the wedge increases with the duration of a low-productivity report. We apply the methods to numerically solve the Mirrleesian dynamic taxation model, and find that the wedge is significantly larger than that in the independently and identically distributed (i.i.d.) shock case.     

Pessimistic information gathering

An agent gathers information on productivity shocks and accordingly produces on behalf of a principal. Information gathering is imperfect and whether it succeeds or not depends on the agent's effort. Contracting frictions come from the fact that the agent is pessimistic on the issue of information gathering, and there are both moral hazard in information gathering, private information on productivity shocks and moral hazard on operating effort. An optimal menu of linear contracts mixes high-powered, productivity-dependent screening options following “good news” with a fixed low-powered option otherwise.     

A simple explanation of the relative performance evaluation puzzle

We study a simple moral hazard model in which two risk-neutral owners establish incentives for their risk-averse managers to exert effort. Because the probability distributions over output realizations depend on a common aggregate shock, optimal contracts make the compensation of each manager contingent on own performance but also on a performance benchmark—the performance of the other firm. If the marginal return of effort depends on the aggregate state, optimal contracts are not monotonically decreasing in the performance benchmark. This provides a simple explanation of the Relative Performance Evaluation (RPE) Puzzle—the documented lack of a negative relationship between CEO compensation and comparative performance measures, such as industry or market performance. Our simple model can also explain one-sided RPE—the documented tendency to insulate a CEO's rewards from bad luck, but not from good luck. We clarify that our results are robust in several dimensions and we discuss other applications of our findings.     

Workers' compensation: Determining a feasible payment structure in a regulatory environment

Moral hazard complicates the design of an optimal benefit structure in a regulated social insurance program such as workers' compensation. We discuss the type of empirical information necessary to set optimal benefit levels in the presence of moral hazard. Since we present trends in indemnity and medical expenditures that indicate the presence of claims rate moral hazard, we develop and estimate a model of this type of moral hazard. We find evidence of moral hazard effects that are roughly consistent with those found elsewhere in the literature. We also present the first direct estimates of the impact of benefits on the output of the firm. We find that an increase in real benefits significantly decreases the output of the firm. This is consistent with notion that higher benefits induce more jobless spells and increase production costs using skilled labor. We close by illustrating how these estimates can be used to provide information on the feasible benefit schedule, given the presence of moral hazard.     

Moral Hazard and Adverse Selection in Procurement Contracting

A model of procurement contracting is developed and tested in laboratory experiments. Market performance results are presented for both fixed-price and cost-sharing contracts. Contracts are awarded with first-price sealed-bid or second-price sealed-bid auctions. The environment contains post-auction cost uncertainty and opportunity for unmonitored effort in contract cost reduction. Cost-sharing contracts are found to reduce procurement expense but also to be inefficient because of their induced moral hazard waste and cost overruns.Journal of Economic LiteratureClassification Numbers: C72, C92, D44, D61, D82, H57, L14.     

Risk-bearing and entrepreneurship

In the “Knightian” theory of entrepreneurship, entrepreneurs provide insurance to workers by paying fixed wages and bear all the risk of production. This paper endogenizes entrepreneurial risk by allowing for optimal insurance contracts as well as occupational self-selection. Moral hazard prevents full insurance; increases in an agent's wealth then entail increases in risk borne. Thus, even under decreasing risk aversion, there are robust instances in which workers are wealthier than entrepreneurs. This empirically implausible result suggests that risk-based explanations for entrepreneurship are inadequate.     

Optimal supervision with moral hazard

This paper adopts the principal–supervisor–agent hierarchy model pioneered by Tirole [Tirole, J., 1986. Hierarchies and bureaucracies: on the role of collusion in organizations. Journal of Law, Economics and Organization 2, 181–214] to analyze the optimal architecture of supervision. We consider a principal who encounters a double moral hazard problem. In particular, we examine the endogenously determined supervisory effort and the possibility of untruthful revelation of supervisor's message. The degree of accuracy for this endogenously chosen information architecture hinges upon the supervisory technology, the supervisor's reservation utility and the agent's production technology. Besides, though the principal's welfare would be lowered when the possibility of untruthful revelation is taken into account, we find that his desired supervisory effort level may be enhanced instead.     

Collective Organizations versus Relative Performance Contracts: Inequality, Risk Sharing, and Moral Hazard

This paper studies collective economic organizations that share risk and mitigate moral hazard and compares them with relative performance contracts. Information-constrained optimal distributions of organizations and contracts are shown to be functions of the underlying primitives, in particular, the distribution of Pareto weights, and hence degree of inequality. Internal inequality of a potential, local group is a force for collective organization. That is, multi-agent organizations exist in order to extract wealth from some but not necessarily all members. The group organization is also shown to be information-constrained Pareto optimal at extremes of local wealth relative to an outsider. But the group organization is susceptible to both agents simultaneously deviating, colluding against the outsider, and this distortion makes an individualistic, relative performance contract an attractive alternative. More generally, organizations, contracts, and allocations are jointly determined. These implications could be distinguished in cross-sectional, time series data. Journal of Economic Literature Classification Numbers: D70, D82.     

基于委托代理理论的信用违约互换最优契约模型分析

本文阐述了信用风险互换及其委托代理关系．分析了信息不对称下引起信用违约互换道德风险问题，运用委托代理理论建立了相应的信用违约互换契约分析模型．对道德风险下的最优信用违约契约性质进行研究．并提出了解决道德风险、优化信用违约互换的激励机制．确保信用违约互换在我国的健康发展。     

NONSTATIONARY RELATIONAL CONTRACTS WITH ADVERSE SELECTION*

I develop a model of nonstationary relational contracts in order to study internal wage dynamics. Workers are heterogeneous, and each worker’s ability is both private information and fixed for all time. Learning therefore occurs within employment relationships. The inferences, however, are confounded by moral hazard. Incentive provision is restricted by an inability to commit to long‐term contracts. Relational contracts, which must be self‐enforcing, must therefore be used. The wage dynamics in the optimal contract, which are pinned down by the tension between incentive provision and contractual enforcement, are intimately related to the learning effect.     

Time of the essence

In most industries, ranging from information systems development to construction, an overwhelming proportion of projects are delayed beyond estimated completion time. This fact constitutes somewhat of a puzzle for existing theory. The present paper studies project delays and optimal contracts under moral hazard in a setting with time to build. Within this setup, project delays are found to be most likely to happen at early stages of development and intimately connected to the degree of commitment of the procurer and the class of contracts that can be enforced. The first-best, optimal spot contracting and optimal long-term contract scenarios are analyzed, as well as commonly encountered additional constraints on the long-term contract.     

Moral Hazard and Bargaining Power

Abstract. We introduce bargaining power in a moral hazard framework where parties are risk-neutral and the agent is financially constrained. We show that the same contract emerges if the concept of bargaining power is analyzed in either of the following three frameworks: in a standard principal–agent (P–A) framework by varying the agent's outside opportunity, in an alternating offer game, and in a generalized Nash-bargaining game. However, for sufficiently low levels of the agent's bargaining power, increasing it marginally does affect the equilibrium in the Nash-bargaining game, but not in the P–A model and in the alternating offer game.     

Optimal incentive contracts under inequity aversion

We analyze the classic moral hazard problem with the additional assumption that agents are inequity averse. The presence of inequity aversion alters the structure of optimal contracts. When the concern for equity becomes more important, there is convergence towards linear sharing rules. The sufficient statistics result is violated. Depending on the environment, contracts may be either overdetermined, i.e. include non-informative performance measures, or incomplete, i.e. neglect informative performance measures. Finally, our model delivers a simple rationale for team based incentives, implying wage compression.     

风险投资家的最优激励契约模型研究--一种基于逆向选择和道德风险条件下的博弈模型分析

为减少风险投资融资中风险投资家的逆向选择和道德风险,风险投资者必须设立一套有效的激励机制来让风险投资家选择,从而根据风险投资家选择的结果来甄别其真实能力类型,同时又能激励其努力工作。文章建立了风险投资家能力类型和努力都是不可观测条件下的最优激励契约模型,并根据显示原理,利用最优控制理论求出了最优解进而进行了分析。得出的结论是:最优激励契约能使高能力风险投资家乐于选择具有高强度激励、低固定收入和风险小的项目,同时又能激励其签约后更加努力工作。     

Mechanism design for general screening problems with moral hazard

Summary We study the problem faced by an incomplete information monopolist seeking to design a line of contracts so as to simultaneously screen consumers by type and resolve the moral hazard problems associated with contract performance. We formulate the monopolist's problem as a mechanism design problem in which the set of consumer types is taken to be a Polish space, and the contract space an arbitrary compact metric space. Allowing for risk aversion on the part of the monopolist and consumers, and taking as the feasible set of mechanisms the collection of all measurable functions defined on the space of consumer types with values in the space of contracts, we present a new characterization of incentive compatibility in an infinite dimensional setting which allows us to reformulate the monopolist's design problem as an unconstrained optimization problem (i.e., as a problem without the incentive compatibility contraints). Using simple techniques, we then demonstrate the existence of an optimal screening mechanism for the monopolist. We thus extend the existing analysis of the incomplete information monopoly problem to an infinite dimensional setting with moral hazard, and we provide an existence result not available in the existing literature.I thank seminar participants at Indiana University, McGill University, and the University of Calgary for helpful comments. I also thank Kerry Back, Bob Becker, Praveen Kumar, Mark Johnson, Ramon Marimon, Murat Sertel, Bill Sealey, Gordon Sick, and Nicholas Yannelis for helpful comments. The comments and suggestions of an anonymous referee are especially appreciated. I am solely responsible for any errors.