2014年-世界发展银行全球_Economic_Resilience___Definition_and_Measurement_46页_1mb

Economic Resilience: Definition and Measurement

Core Content

This paper by Stephane Hallegatte explores the concept of economic resilience to natural disasters, emphasizing its importance in minimizing welfare losses. It distinguishes between macroeconomic resilience and microeconomic resilience, and proposes a framework for measuring and improving both.

Main Points

1. Definition of Economic Resilience

• Economic resilience refers to the ability of an economy to cope, recover, and reconstruct after a natural disaster, thereby minimizing aggregate consumption losses.
• It includes two components:
  • Instantaneous resilience: The ability to limit the magnitude of immediate income loss for a given level of asset loss.
  • Dynamic resilience: The ability to reconstruct and recover quickly over time.

2. Welfare Impact of Disasters

• The welfare impact of a disaster is not only determined by the physical characteristics of the event or direct losses (e.g., lives and assets), but also by the resilience of the economic system.
• Disasters have economic consequences that include:
  • Loss of output and production.
  • Loss of income and livelihood.
  • Rationing in certain sectors.
  • Loss of employment and tax revenues.
• These economic losses must be considered alongside human losses to fully assess disaster impact on welfare.

3. Asset Losses vs. Output Losses

• Asset losses refer to the value of damaged or destroyed capital (e.g., buildings, infrastructure).

• Output losses are the reduction in production or services due to asset loss, and include:

  • Business interruptions.
  • Direct production losses.
  • Supply chain disruptions.
  • Macroeconomic feedbacks.
  • Long-term effects on growth.
  • Reconstruction booms.

• Output losses are not always equal to asset losses. In an idealized economic setting, the relationship is:
  $$
  \Delta Y(t_0) = r \Delta K
  $$
  where $r$ is the marginal productivity of capital (equal to the interest rate plus depreciation rate).

• However, in realistic scenarios, output losses are larger than asset losses due to:

  • Non-marginal shocks: Where the destruction affects more productive assets.
  • Externalities and distortions: Where the social value of an asset exceeds its market value (e.g., public goods).
  • Ripple effects: Indirect impacts on non-affected assets through supply chain and sectoral disruptions.

Key Information

1. Challenges in Measuring Economic Resilience

• GDP is often used as an indicator of output loss, but it has limitations:

  • It does not capture non-market production or household services.
  • It fails to reflect wealth or distributional effects.
  • It is insensitive to local shocks in large countries.

• A better approach involves using a modified production function that accounts for:

  • Decreasing returns to scale.
  • Externalities.
  • Path dependency and market distortions.

2. Proposed Framework

• The paper proposes a framework to estimate output losses using the following formula:
  $$
  \Delta Y(t_0) = \frac{1}{\mu} r \Delta K
  $$
  where $\mu$ is a parameter reflecting decreasing returns to scale.

• This framework is more accurate for non-marginal shocks and accounts for ripple effects and supply chain disruptions.

3. Policy Implications

• The paper suggests tools and indicators to measure economic resilience:

  • Macro indicators: Reflect the economy’s ability to limit immediate and long-term losses.
  • Micro indicators: Reflect household-level resilience, including:
    • Distribution of losses.
    • Household vulnerability (e.g., pre-disaster income).
    • Ability to smooth shocks through savings, borrowing, and insurance.
    • Social protection mechanisms.

• It emphasizes the importance of early warning systems and reconstruction efficiency in reducing disaster costs.

4. Resilience and Development Goals

• The paper aligns with the post-2015 Sustainable Development Goals and the Hyogo Framework for Action, highlighting the need for resilience indicators to guide resource allocation and policy design.
• It proposes proxies and indicators for economic resilience, with a focus on measurability and relevance.

Summary of the Paper Structure

• Figure 1 outlines the structure of the welfare disaster risk assessment, emphasizing the integration of hazard, exposure, vulnerability, and resilience.
• Figure 2 illustrates the theoretical equivalence between asset loss and output loss in the absence of reconstruction.
• Figure 3 shows the impact of capital loss on production under different assumptions, including marginal and non-marginal shocks.

Conclusion

• The paper provides a practical and simplified framework for estimating economic resilience, acknowledging the complexity of real-world systems.
• It calls for the development of meaningful and measurable resilience indicators, which can support policy discussions and resource allocation.
• The focus is on economic resilience, while noting that non-economic dimensions (e.g., health and social impacts) are also important but not the main subject of the paper.