A Study On Contract In Design-Build Delivery Mode Based On Principal-Agent Theory

Design-Build delivery mode is one way of general contract. It is very extensive to apply, and make very good result in the world. Compared with traditional mode, designing and building is in the charge of one unit, thus there are greater advantages in project contracting. But DB mode has some shortcomings, having restricted its healthy and fast development. Principal-agent theory is the most important development of the contract theory in the past 20 years. It studies how to design the contract between principal and agent effectively, to make cost minimum. In DB mode, the owner can be regarded as the principal, the contractor can be regarded as the agent. Principal-agent theory can effectively settle the problem that the contractor is apt to think for himself or be lazy to reduce the owner's benefit. This paper has carried on research to DB mode in terms of this, and through principal-agent theory model to calculate and put forward the solutions.First of all, this paper explains forming and development of DB mode in detail, analyzes its advantages and disadvantages, and introduces development and application of principal-agent theory. It lays the thesis's foundation through the principal-agent relationship analysis in DB mode. Secondly, the thesis adopts the moral hazard with hidden action model put forward by Mirrlees in 1974 and perfected by Holmstrom, which is the most widely used and ripely developed one in the principal-agent models. On the basis of this model, the thesis designs different parameters for unique characteristics of DB mode, and calculates the concrete parameter model to obtain the optimal key. Thirdly, through explaining the parameters in the optimal key, the thesis optimizes articles in four aspects: project quality, project schedule, changing and payment-controlling, then deduces the final production.Finally, based on foregoing study, the thesis analyzes a case of General Contract in Hangzhou Goldfish electric apparatus company's moving project. Through optimizing the contract, design the encouragement contract which accords with the actual conditions of this project.