2013年-世界发展银行全球_Cost_Benefit_Studies_on_Disaster_Risk_Reduction_in_Developing_Countries_20页_663kb

Summary of EAP DRM KnowledgeNotes: Cost Benefit Studies on Disaster Risk Reduction in Developing Countries

Core Content

This working paper provides an overview of cost-benefit analysis (CBA) studies on disaster risk reduction (DRR) interventions in developing countries, highlighting the economic and social benefits of such measures. It emphasizes the shift in focus from disaster recovery to risk reduction over the past decade, particularly in the context of the Hyogo Framework for Action (HFA) 2005-2015. The paper aims to offer insights into the strengths and limitations of existing DRR economic studies, with a focus on developing countries.

Main Viewpoints

• Shift in Focus: Development actors have increasingly prioritized disaster risk reduction over disaster recovery.
• Cost-Effectiveness: DRR measures are generally found to be more cost-effective than post-disaster recovery, with benefits often significantly outweighing costs.
• Need for Better Analysis: There is a growing recognition of the need for more rigorous and comprehensive economic analysis of DRR measures.
• Limitations of CBA: The use of CBA in DRR is limited due to issues such as lack of data, difficulty in monetizing intangible benefits, and uncertainty in modeling future risks.
• Distributional Analysis: Few studies analyze how DRR benefits and costs are distributed among different socio-economic groups, particularly the poor and vulnerable.

Key Information

1. Methodology and Metrics

• Units of Analysis: Most studies use structures (e.g., buildings, schools) as the unit of analysis, while some focus on projects, districts, or national levels.
• Quantitative vs. Qualitative: 16 out of 17 studies use quantitative methods, with three combining qualitative and quantitative approaches.
• Metrics Used: Common metrics include Benefit-Cost Ratio (BCR), Internal Rate of Return (IRR), and Net Present Value (NPV). Some studies also use loss exceedance curves and Pure Risk Premium.
• Discount Rates: Discount rates range from 3% to 20%, with most studies using 12% or 10%. A few studies do not use discount rates.

2. Sources of Uncertainty

• Data Limitations: Lack of reliable historical hazard and vulnerability data is a major challenge in conducting CBA.
• Indirect Losses: Indirect losses (e.g., business interruptions, loss of livelihoods) are rarely accounted for.
• Climate Change: Climate change introduces deep uncertainties, making it difficult to predict future risks and adapt DRR measures accordingly.
• Sensitivity Analysis: Most studies perform sensitivity analysis by varying discount rates, costs, benefits, and other parameters.

3. Valuation of Fatalities and Injuries

• Monetization of Lives: Some studies attempt to monetize the value of lives saved, using local wage rates or exchange rates.
• Developed vs. Developing Context: Developed countries often assign high monetary values to fatalities (e.g., $3 million per fatality), while many developing country studies either avoid monetizing them or use simpler methods.
• Importance of VSL: The Value of a Statistical Life (VSL) is a critical concept for assessing the economic value of DRR interventions, especially in developing countries.

4. Results

• Cost-Benefit Outcomes: Most studies show that DRR measures yield higher benefits than costs.
• Examples of Benefits:
  • In Jamaica, including earthquake-resistant features in building design would have cost less than 3% of building costs, with benefits up to 40%.
  • In the Philippines, the benefit cost ratio for rain forestation was 30, while bamboo plantation had a BCR of 14.7.
  • In Vietnam, mangrove protection cost $1.1 million but saved $7.3 million annually in dyke maintenance.
• IRR and BCR: IRR and BCR vary significantly across studies, with some reaching as high as 79% and 30, respectively.

5. Distributional Analysis

• Vulnerable Groups: Some studies acknowledge the importance of considering vulnerable groups, such as the poor, women, and children.
• Limited Disaggregation: Few studies explicitly disaggregate data by socio-economic groups, making it difficult to assess how different populations are affected.
• Social Vulnerability: Research suggests that women, children, and marginalized groups are disproportionately affected by disasters and may benefit more from DRR measures.

Recommendations

• Develop Clear Guidelines: Establish standardized protocols for conducting CBA in DRR, taking into account the unique challenges of developing countries.
• Improve Data Collection: Invest in collecting reliable data on hazards and vulnerabilities to enhance the accuracy of economic analyses.
• Explore Alternative Methods: Consider methodologies like Robust Decision Making (RDM) to address deep uncertainties in DRR.
• Enhance Distributional Analysis: Conduct more research on how DRR interventions affect different socio-economic groups to ensure equitable outcomes.

Conclusion

The paper concludes that while CBA is a valuable tool for DRR decision-making, it is often limited by data and methodological constraints. A strategic shift towards ex-ante risk reduction is essential, but more work is needed to ensure that DRR investments are both economically sound and socially inclusive.