A central bank is usually assigned two functions: the control of inflation and the maintenance of a safetybanking sector. What are the precise conditions under which trigger strategies from the private sector can solve the time inconsistency problem and induce the central bank to choose zero inflation under a nonstationary natural rate? Can an optimal contract be used together with reputation forces to implement a desired socially optimal monetary policy rule? How to design a truthtelling contract to control the risk taking behaviors of the bank? My dissertation attempts to deal with these issues using three primary methodologies: monetary economics, game theory and optimal stochastic control theory.

A central bank is usually assigned two functions: the control of inflation and the maintenance of a safetybanking sector. What are the precise conditions under which trigger strategies from the private sector can solve the time inconsistency problem and induce the central bank to choose zero inflation under a nonstationary natural rate? Can an optimal contract be used together with reputation forces to implement a desired socially optimal monetary policy rule? How to design a truthtelling contract to control the risk taking behaviors of the bank? My dissertation attempts to deal with these issues using three primary methodologies: monetary economics, game theory and optimal stochastic control theory.

Après une introduction générale et un survey de littérature, l’apport de cette thèse est d’établir un lien entre le marché des biens et le marché de travail et de proposer un système légal optimal pour dissuader les comportements opportunistes au sein de l’entreprise. Tout au long de la thèse, le cadre d’analyse utilisé est le cas d’un monopole qui produit deux types de biens. Les consommateurs sont hétérogènes selon leurs préférences à la qualité. Le chapitre 2 analyse différentes structures d’agence afin de déterminer la meilleure structure qui permet à la fois de maximiser le profit de l’entreprise et de maximiser le bien-être des consommateurs et des employés. Le chapitre 3 examine la distorsion de la qualité des biens et du niveau d’effort des employés en asymétrie d’information avec sélection adverse sur le marché des biens et le marché de travail par rapport à l’information parfaite. Le chapitre 4 étend le chapitre 3 en étudiant la même problématique avec un problème d’aléa-moral sur le marché de travail en présence d’une collusion entre le superviseur et l’employé. Ce chapitre questionne le rôle du consommateur et du juge à dissuader cette forme de comportement opportuniste. / After a general introduction and a survey of literature, the contribution of this thesis is to establish a link between the goods market and the labor market and to propose optimal legal system to deter opportunistic behavior within the company. Throughout the thesis, we consider a monopoly that produces two types of good. Consumers are heterogeneous according to their preferences to quality. Chapter 2 analyzes different agency structures to determine the best structure that allows both to maximize the profit of the company and maximize the welfare of consumers and employees. Chapter 3 examines distortion of the quality of goods and the level of the workers’ effort with adverse selection on the goods market and the labor market compared with perfect information. This chapter examines the role of the consumer and the judge to discourage this kind of opportunistic behavior.Keywords: Quality of goods, quality of labor, optimal contract, portfolio of contract, opportunism, collusion, social welfare, optimal sanctions, firm design, law and economics.

The architecture, engineering and construction industry faces challenges when dealing withprocurement contract design and risk-handling. The optimal contracting practices have beenworldwide studied in areas of contract theory which studies how the optimal incentivemechanism (“contracts”) can be designed to encourage the parties to behave more efficiently.The parties usually consist of a principal and an agent, where the principal hires an agent todeliver goods or services. However, the complexity of contract theory calls for a morepracticable approach in an attempt to understand the procurement problem in the industry andincrease knowledge-sharing between projects. The purpose of this study is to propose a model based on contract theory that can be used inpractice to investigate the effects of project endogenous risks in three different types ofprocurement contracts: fixed-price, time and material, and incentive. Thus, this study usesquantitative methods with the aim to explain the current procurement problem in the Swedisharchitecture, engineering, and construction industry, compare theory and practice, andcontribute to knowledge about the linkage between endogenous risks, optimal risk sharing andcontract design. The conclusions from this study are that the current contracting practices in the industry arenot aligned with the optimal contract design described by the theory. The theory in this researchshowed that, given endogenous project risks, the optimal incentives vary in the agent’saversion to risk resulting in a non-monotone relationship between optimal contract power andproject risk. Further, a contract becomes optimal and efficient when cost savings and qualityincentives are aligned. However, the analysis of real-world projects presented no clearrelationship between contract power and project risk, i.e. some projects with fixed-pricecontracts or time and material contracts presented the same risk level. Hence, this researchproposes a method for computing the optimal incentive contract which can be used in manycases where the other two types of contract are currently being used. Based on the theory, theoptimal incentive contract may add valuable benefits for both parties involved since it aims toefficiently share the project risk between them while providing the agent the right incentivesto work more efficiently to reduce costs and deliver high-quality services or goods. / Byggbranschen står inför utmaningar när det gäller kontraktsdesign och riskhantering. Deoptimala upphandlingsmetoderna har studerats över hela världen inom områden avkontraktsteori som i sin tur studerar hur den optimala incitamentsmekanismen ("kontrakt") kanutformas för att uppmuntra parterna att agera mer effektivt. Parterna består vanligtvis av enprincipal och en agent, där principalen anställer en agent för att leverera varor eller tjänster.Men komplexiteten i kontraktsteori kräver ett mer praktiskt tillvägagångssätt i ett försök attbättre förstå upphandlingsproblemet i byggbranschen samt att öka kunskapsutbytet mellanprojekt. Syftet med denna studie är att föreslå en modell baserad på kontraktsteori som kan användas ipraktiken för att undersöka effekter av endogena risker i tre olika typer avupphandlingskontrakt: fastpris, rörligt pris (time and material) och incitament. Denna studieanvänder därmed kvantitativa metoder i syfte att förklara det aktuella upphandlingsproblemeti den svenska byggbranschen, jämföra teori och praktik, och bidra till utökad kunskap omsambandet mellan endogena risker, optimal riskdelning och kontraktsdesign. Slutsatsen från denna studie är att den nuvarande upphandlingspraxisen i branschen inte är ilinje med den optimala kontraktsdesignen som beskrivs av teorin. Teorin i denna studie visaratt, förutsatt endogena projektrisker, så varierar de optimala incitamenten med agentensriskaversion vilket resulterar i ett icke-monoton förhållande mellan optimal kontraktsdesignoch projektrisk. Dessutom blir ett kontrakt optimalt och effektivt när kostnadsbesparingar ochkvalitetsincitament är i linje med varandra. Men analysen av verkliga projekt visar inget tydligtsamband mellan kontraktsdesign och projektrisk, det vill säga en del projekt med fastpris ellerrörligt pris visade sig ha samma risknivå. Därför föreslår denna studie en metod för beräkningav det optimala incitamentet som kan användas i många fall där de andra två typerna avkontrakt för närvarande används. Teorin säger att det optimala incitamentet kan ge värdefullafördelar för de inblandade parterna eftersom det syftar till att på ett effektivt sätt fördelaprojektrisken mellan dem samtidigt som agenten får rätt incitament att arbeta mer effektivt föratt sänka kostnaderna och leverera högkvalitativa tjänster eller varor.