2012年-世界发展银行全球_Density_and_Disasters___Economics_of_Urban_Hazard_Risk_32页_309kb

Summary: Density and Disasters: Economics of Urban Hazard Risk

Core Content

This paper explores the economics of urban hazard risk, focusing on how the concentration of people and assets in cities increases vulnerability to natural disasters. It argues that while hazard risk cannot be eliminated, it can be mitigated through better urban management and public policy. The authors highlight the role of agglomeration economies in encouraging urban growth and how this concentration changes the cost-benefit analysis of hazard mitigation. They also emphasize the need for the public sector to provide credible hazard information to support market-based risk reduction strategies.

Main Points

• Urban Hazard Risk is Growing:

  • By 2050, the number of people living in cities prone to earthquakes is expected to increase from 370 million to 870 million.
  • For tropical cyclones, the number is projected to rise from 310 million to 680 million.
  • Urban areas are becoming more exposed due to population and economic growth, even though this growth may not necessarily increase total global exposure.

• Hazard Risk in Cities is Higher:

  • Cities are more vulnerable due to high population density, economic concentration, and the presence of critical infrastructure.
  • Urban areas are often located in geographically hazardous zones (e.g., coastal areas, volcanic regions) due to historical and economic factors.
  • Exposure is also increased by land scarcity and the tendency for low-income populations to settle in high-risk areas.

• Economic Factors Influence Risk:

  • Agglomeration economies (increased productivity and efficiency) encourage urban growth and concentration.
  • These economies can reduce the impact of hazard risk by improving infrastructure, institutions, and coping capacity.
  • However, they also mean that hazard risk is more significant in cities than in rural areas.

• Risk Valuation in Property Markets:

  • Natural hazard risk is reflected in real estate prices, especially when risk awareness is high.
  • Studies show that property values decrease in high-risk areas, and mitigation investments are capitalized into property prices.
  • Informal settlements often have higher risk exposure due to poor construction and lack of regulation.

• Policy Implications:

  • Municipal Management: Governments must manage land use, drainage, public buildings, and emergency services to reduce risk.
  • Information Dissemination: Public agencies need to provide credible hazard risk information to facilitate private mitigation efforts and avoid information asymmetry.
  • Targeted Interventions: Policies should address the disproportionate risk faced by low-income populations, such as improving access to affordable public transportation and in situ service upgrades.

Key Findings

• Urbanization and Risk:

  • Urban areas are more exposed to natural hazards due to their economic density and concentration of people and assets.
  • Climate change may affect some hazards (e.g., hydro-meteorological events), but the primary driver of increasing urban hazard risk is the continued growth and concentration of exposure.

• Risk and Income:

  • Lower-income groups tend to reside in high-risk urban areas due to lower land prices.
  • This creates a situation where poor populations bear a disproportionate share of hazard risk.

• Market-Based Mitigation:

  • Markets can provide incentives for private mitigation and risk transfer (e.g., insurance).
  • However, market failures may occur due to lack of information, leading to the need for public sector intervention.

• Empirical Evidence:

  • Hedonic models show that property prices reflect hazard risk.
  • In cities like Tokyo, Bogota, and Istanbul, property values are lower near high-risk zones.
  • In the U.S., flood risk disclosure leads to price discounts, similar to flood insurance premiums.

Conclusion

The paper concludes that effective hazard management in cities is essential for sustainable urban development. It emphasizes that good urban management and policy can reduce hazard risk, and that the public sector has a critical role in promoting market-based risk reduction through the provision of accurate and accessible information. The challenge lies in addressing the growing exposure and ensuring that low-income populations are not disproportionately affected by natural hazards.