Research on the optimal planning of investment in construction industry and infrastructures under disaster risk

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14265
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22050:Civil engineering plan and transportation engineering-related
• Research Institution: Kobe University
• Principal Investigator: Segi Shunsuke 神戸大学, 工学研究科, 准教授 (50762382)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 防災 / 建設産業 / マクロ経済 / レジリエンス

Outline of Final Research Achievements

A dynamic macroeconomic model was formulated that explicitly considers the role of the construction industry and disaster risk. Analysis using the model yielded the following insights. When households' risk aversion is sufficiently high, the existence of disaster risk increases the optimal size of the construction industry. Given the high risk premium for disaster insurance observed in reality, this result will apply to Japan. If the optimal size of the construction industry expands as disaster risk increases, the optimal level of infrastructure investment also increases. Furthermore, the rate of increase in the optimal size of the construction industry is higher in rural areas than in metropolitan areas.

Free Research Field

土木計画学

Academic Significance and Societal Importance of the Research Achievements

研究成果の学術的意義は，社会資本や住宅・建築物などの供給を担う建設産業と，災害リスクの存在を明示的に考慮したという点において，独創的なマクロ経済モデルを定式化したことにある．社会的意義としては，建設産業の最適規模と災害リスクの関係に関する，以下のような政策的知見を導いたことにある．まず，異なる国の建設産業の規模を比較する際には，その国が直面する災害リスクの大きさを考慮に入れる必要がある．次に，社会資本投資計画は，建設産業の規模や地理的配置を最適な水準に誘導するうえで，重要な役割を果たし得る．