A Study on Risk Evaluation Caused by Delay of Infrastructure Development Projects

由于当前和未来基础设施发展预算数额的限制，需要对基础设施发展进行有效投资的方法。本研究分析了1）为增加社会福利而提供基础设施的最佳时机，2）考虑到需求增长的两步发展等新的发展程序理念的投资效果，（3）按现行的再开发政策，两步开发和取消开发的效果。日本政府的评估框架考虑到基础设施开发的不可逆性，其中无法收集沉没成本，在单一基础设施发展的情况下，假设未来的利益是不确定的。

The methodology of effective investment for infrastructure development is required due to the limitation of current and future amount of budget for infrastructure developments. This study analyzes 1)the optimal timing for providing infrastructure in order to increase the social welfare, 2)the effect of investment by the new idea of development procedure such as two-step development considering the increase of demand, and 3)the effect of two-step development and cancellation of development according to the current re-evaluation framework by Japanese government considering the irreversible property of infrastructure development in which sank cost cannot be collected, in case of single infrastructure development on the assumption that future benefit will be uncertain.