This study considers a road network where a highway and a local road run in parallel and theoretically analyze the second best pricing of the highway toll. The purpose of the second best pricing is to internalize the external diseconomies of congestion and deterioration of the road structures accompanying the road use. In the analysis, we pay attention to the two facts; one fact is that the influence on the deterioration of the road structures differs between large size cars and standard size cars. The other fact is that the load bearing capacity of the road structures differs between highway and local road. Paying attention to these facts, we analyzed the second best highway toll which minimizes the total social cost including the congestion costs and the road maintenance costs by controlling the route choices of the users. The analysis shows that discriminatory toll pricing of two vehicle types has an important effect to improve the validity of the maintenance cost reduction by toll settings.
This paper discusses the disastrous risk of asset loss by the foot-and-mouth disease and presents a methodology to investigate the strategies to deter spatial infection of foot-and-mouth disease to minimize the expected cost driven by asset loss. The spatial infection process of the diseases is formulated by Markov chain models. Since the model is characterized by a large number of state variables, it is impossible to enumerate all state variables in the form of explicit Markov chain models. The paper proposes to calculate approximate values of risk evaluation indices and find out better strategies which may reduce the expected damage as small as possible by use of quasi Monte Carlo simulation. The availability of the proposed methodology is verified using the case of the outbreak of foot-and-mouth disease in Miyazaki prefecture in 2010.
This study formulates a Markov vintage model, which expresses the transition dynamics of the stock of infrastructure dependent on the infrastructure investment and life-extension investment. With this Markov vintage model, this study formulates a dynamic infrastructure investment model, which gives a normative infrastructure investment policy to maximize the social welfare, taking account of the resource constraint in the macro economy and the contribution of infrastructures to the economic activities. Analyzing the optimal investment policy, this study shows that life-extension investment of infrastructure brings two kinds of economic benefits: stock effect and leveling effect. Stock effect is the benefit to increase the longrun household consumption level. Leveling effect is the benefit to level off the burden of infrastructure renewal cost between generations. Besides, this study considers the properties of the optimal policy of infrastructure investment and life-extension investment through numerical analysis.