Essays on Principal-agent Models


Book Description

This dissertation consists of three chapters on principal-agent models. Chapter 2 studies an optimal contract design problem in a principal-framework whereas chapter 3 is an empirical investigation of the incentive contracts in the market of top executives. Chapter 4 is a theoretical chapter exploring welfare impacts of the structure in a top-level bureaucracy. In the first chapter, I consider a dynamic moral hazard model where the principal offers a series of short-run contracts. I study the optimal mix of two alternative instruments for incentive provision: a performance based wage (a "carrot") and a termination threat (a "stick"). At a given point in time, these instruments are substitutes in the provision of incentives. I am particularly interested in the dynamic interaction of these two instruments. Both carrot and stick are used more intensively as the agent approaches the end of her finite life. The sharing of the surplus of the relationship plays a key role: a termination threat is included in the optimal contract if and only if the agent's expected future gain from the relationship is sufficiently high, compared to the principal's expected future gain. Also, a termination threat is more likely to be optimal if output depends more on "luck" than on effort, if the discount factor is high, or if the agent's productivity is low. Having inspired from chapter 2, chapter 3 of the dissertation is an empirical study of the contracts of Chief Executive Officers (CEO). Direct pay for performance and a threat of termination when performance is low are two important instruments to incentivize CEOs. This chapter is an empirical analysis of the use of these two incentive devices and how they depend on tenure and managerial ability. For managers promoted from within a firm, ability is proxied by their age at the time of promotion. For managers hired from outside, I instead rely on constructed measures of "reputation", based on media citations over time windows of different length. Using a sample of firms, listed in S & P 1500 over the period 1998-2008, I find that CEO compensation and the threat of forced turnover are used as incentive devices throughout tenure. Even though the results indicate that pay increases as the CEO is more senior in her tenure, there is no strong evidence that termination threat follows a particular time pattern. For outsider CEOs, a better reputation increases pay and decreases the likelihood of forced turnover, with stronger effects for more current reputational measures. Regarding the impacts of reputation on the tenure-pay relationship, only more current measures have a significant and negative effect. Managerial ability, as proxied by age-at-promotion for insiders and as proxied by reputation for outsiders, decreases the likelihood of forced turnover. More current reputation measures, as in the case of total pay, have a larger impact of likelihood of turnover. Chapter 4 investigates the welfare implications of multiple principals in the highest level of bureaucracy. An agent has to carry out two separate tasks, which can either be organized by two separate principals, or combined under one principal. The relationship between the top level (the principals) and the lower level (agent) of the bureaucracy is a "principal-agent problem". The existence of multiple principals generates a "common agency". The analysis reveals that the optimal hierarchy depends on the existence of "rents" from office that the principals enjoy. If there are no rents, the two systems are equally welfare-efficient. A single-principal model dominates common agency otherwise.







Essays on Information Transmission in Principal-Agent Models


Book Description

The first chapter explores the "hidden costs of rewards" in a dynamic informed-principal framework. It shows that rewards are "addictive" : once offered, a contingent reward makes the agent expect it in the future. In a long-term relationship there is a two-sided ratchet effect : the principal is concerned about creating addiction for the agent, whereas the agent does not want to appear too enthusiastic. The second chapter suggests a rationale for paying discretionary bonuses in finitely repeated principal-agent interactions. If the principal cannot commit to contingent rewards, he may still pay discretionary bonuses to give the agent credible feedback about his performance. The third chapter investigates the credibility of advice of a broker, who mediates trade between a seller and a buyer and is partially informed about the buyer's valuation. We derive the optimal direct mechanism maximizing the broker's profit, and investigate information transmission in a decentralized mode.










Essays in Accounting Theory in Honour of Joel S. Demski


Book Description

The integration of accounting and the economics of information developed by Joel S. Demski and those he inspired has revolutionized accounting thought. This volume collects papers on accounting theory in honor of Professor Demski. The book also contains an extensive review of Professor Demski’s own contributions to the theory of accounting over the past four decades.










Essays on Mechanism Design and the Informed Principal Problem


Book Description

Three models of a privately informed contract designer (a principal) are examined. In the first, I study how much private information the principal wants to acquire before offering a contract to an agent. Despite allowing her to acquire all information for free, I prove in a general environment that there is a nontrivial set of parameters for which it is strictly suboptimal for the principal to be completely informed, regardless of the continuation equilibrium following any information acquisition choice. This result holds even when the principal is able to employ the most general mechanisms available and, in particular, when she can choose her most favourable full-information continuation equilibria. Further, in a specialized environment I characterize the principal's optimal information choice. The second is a two-state principal-agent model with moral hazard in which the principal knows the state but the agent does not. This model is relevant to situations where an employer has private information about the productivity of a worker in a particular task while the worker has private information about the effort she exerts on the job. Much of the literature on this subject restricts the employer to offer contracts that leave her no discretion once a contract is accepted, while more general contracts may allow the employer to exercise discretion after acceptance; such contracts are called menu-contracts. I show when the employer can obtain strictly higher expected payoffs by offering menu-contracts than by offering the restricted contracts used in the literature. The final model studies the ability of a bidder in an auction to organize collusion among her rival bidders and the resulting impact of this collusion on the seller. Bidders valuations are private information. I show that in a two bidder, discrete, independent private-value auction, the seller earns less when a bidder can offer her rival a collusion proposal than in the absence of collusion. This contrasts with a cele- brated result by Che and Kim ("Robustly collusion-proof implementation". Econometrica, 74(4):1063-1107, July 2006) stating that for such auctions there is a mechanism that eliminates all the effects of collusion. Che and Kim and much of the literature assume an uninformed third-party organizes collusion.




The Economics of Contracts


Book Description

A concise introduction to the theory of contracts, emphasizing basic tools that allow the reader to understand the main theoretical models; revised and updated throughout for this edition.