IMF-气候变化下自然灾害抗灾投资的宏观经济回报：DSGE方法（英）-2023.6-49页_1mb

Summary of "The Macroeconomic Returns of Investment in Resilience to Natural Disasters under Climate Change: A DSGE Approach"

Introduction

This paper analyzes the macroeconomic returns of investing in resilient infrastructure to mitigate the impacts of natural disasters (NDs) and climate change using a Dynamic Stochastic General Equilibrium (DSGE) model. The model is calibrated to Dominica's economy and incorporates features such as Markov switching regimes, financial frictions, incomplete markets, foreign remittances, and a full set of fiscal policy instruments to assess the costs and benefits of adaptation investments.

Methodology

The DSGE model employs a Markov-switching framework to account for the recurrent and stochastic nature of NDs, allowing agents to internalize climate risks. Key innovations include endogenous climate risk premiums, collateral constraints, and sensitivity analyses. Calibration uses macroeconomic data and ND frequency estimates, with results derived from impulse response functions and comparative static exercises.

Key Findings

• NDs cause significant and persistent negative impacts on output, public finances, and debt, with output recovery taking approximately five years post-shock.
• Adaptation investments in resilient infrastructure yield substantial returns in the long run, boosting private investment, employment, output, and tax revenues by up to 6-10% in Dominica.
• Climate change intensifies ND impacts, but resilient investments provide higher benefits, with GDP increases of up to 10% compared to non-adaptation scenarios.
• Sensitivity analyses show that factors like public reconstruction speed up recovery but worsen debt, while distortionary taxes and adjustment costs delayed output recovery.

Conclusion

The model underscores the importance of resilience investments for climate adaptation, emphasizing their role in enhancing macroeconomic stability and fiscal sustainability in climate-vulnerable small states like Dominica.