In this paper, the contract schemes for construction projects in the developing countries are formulated in the form of an incomplete contract model, whereby the double moral hazard issues driven by the owners as well as contractors are investigated. The effort levels of the owners and the contractors are supposed to be unverifiable and mutually complementary with respect to costs risk reduction. It is shown that the moral hazard by the owner, who transfers the excessive cost overrun caused by the owner's indulgence to the contractor, may trigger the moral hazard by the contractor; thus, the moral hazard issues by the owner may lead to the overall inefficiency of the project. In this paper, the optimal procurement contract scheme between the owner in the developing countries and the contractor, which can deter the double moral hazard issues and enhance the project efficiency, is theoretically investigated.
In this study, a model which estimates stochastic traffic capacity from observed traffic data is presented. Stochastic capacities during winter and summer in cold region are then estimated by using observed traffic data by a model which is also presented in the present study. A traffic assignment model which has been developed by the authors is used for examining the impact of stochastic capacity on travel times in a road network.
This paper shows the bifurcation (emergence of agglomeration) properties of multi-regional core-periphery (CP) models that extend two-regional CP models developed in the New Economic Geography (NEG). Theoretical studies in the NEG have been almost exclusively limited to the two-regional models, which is a direct result of technical difficulties that inevitably arises in examining a bifurcation of a multi-regional model. In order to overcome these difficulties, we provide an analytical approach that is characterized by a spatial discounting matrix, discrete Fourier transformation, and a system of regions on a circumference. It is shown that the proposed method allows us to readily understand the bifurcation mechanism. Furthermore, we present the detailed evolutionary process of spatial patterns by systematic numerical experiments which is based on the computational bifurcation theory.
A novel method of estimating interregional physical distributions focusing on repercussions is proposed in this study. Physical distribution is viewed from two perspectives: derived and induced physical distribution. These concepts enable the evaluation of the relationship between industrial structure and physical distribution. Using the “Physical Distribution Census” published by the National Land and Transportation Ministry in Japan, methods of calculating physical distribution induced by a unit of final demand and physical distribution derived by a unit of production are developed. This framework can be considered as an input-output analysis of physical distribution, which combines physical distribution with either industrial production or household consumption. A case study of derived physical distribution shows that a ton of final demand of metal and machinery product in Tokyo generates 10.7 ton of physical distribution. Visualized result shows that supply transport disperses many place such as Osaka, Aichi or Chiba. A case study of induced physical distribution shows that a ton of production of farm and marine product in Hokkaido generates 2.5 ton of physcal distribution. Visualized result depicts that farm and marine products are processed and transported to many regions in Japan from Hokkaido. Then, we compare the estimated and actual amount of interregional transport between 47 prefectures in Japan over a year. We can validate our method since estimated transports fit well to actual transport.