2012年-世界发展银行全球_Using_Contingent_Valuation_in_the_Design_of_Payments_for_Environmental_Services_Mechanisms___A_Review_and_Assessment_27页_307kb

Summary of "Using Contingent Valuation in the Design of Payments for Environmental Services Mechanisms: A Review and Assessment"

Core Content

This paper reviews and evaluates 25 contingent valuation (CV) studies conducted in the context of payments for environmental services (PES) programs, particularly those focused on watershed protection. The primary objective is to assess the quality and usefulness of these studies for designing effective PES mechanisms.

PES programs are a market-based approach to conservation financing, where downstream users (e.g., water utilities, hydroelectric power producers) pay upstream landholders to adopt environmentally beneficial practices. These programs aim to internalize externalities and align the self-interest of service users and providers. The paper highlights that while CV surveys are widely used to estimate willingness to pay (WTP) for environmental services, most CV-PES studies suffer from methodological shortcomings, limiting their policy relevance.

Main Views

• Willingness to Pay (WTP) vs. Willingness to Accept (WTA): Most CV-PES studies focus on estimating WTP from downstream users, while fewer examine WTA from upstream providers. The paper emphasizes the importance of both in determining the feasibility of PES programs.
• Feasibility and Welfare Assessment: CV studies can help assess whether a PES program is economically viable and whether it would improve welfare by estimating the value of environmental services to users.
• Price Determination: CV studies can also guide the setting of appropriate prices for services, ensuring that they are both economically viable and socially acceptable.
• Political Feasibility: CV studies can reassure policymakers that users are willing to pay for the benefits they receive, which is crucial for the political acceptance of PES programs.

Key Information

• Methodological Issues: Most CV-PES studies are of low quality, often lacking good practices such as reducing hypothetical bias, using visual aids, and addressing uncertainty.
• Geographic Focus: The majority of the reviewed studies are from Latin America, with ten from Mexico and five from Costa Rica. Only one study is from Africa and two from Southeast Asia (the Philippines).
• Survey Design: The paper outlines nine indicators of good practice for CV studies in the PES context, including:
  • Reducing hypothetical bias using techniques like split-samples and debriefing questions.
  • Assessing respondents' uncertainty through specific questions.
  • Determining whether respondents are "in the market" by using a sequence of follow-up questions.
  • Using visual aids to explain the CV scenario.
  • Testing the robustness of results with scope tests.
  • Assessing the positive correlation between income and WTP.
  • Addressing intrahousehold allocation issues.
  • Obtaining informed consent from respondents.

Special Challenges in CV-PES Studies

• Scientific Uncertainty: It is difficult to predict the exact impact of upstream land use changes on downstream water services. This uncertainty can affect WTP estimates.
• Institutional Uncertainty: Respondents may lack trust in the institutions that will manage and distribute payments, which can influence their willingness to participate in PES programs.
• Multiple Preferences: Downstream users may value watershed protection not only for improved water services but also for non-use benefits such as biodiversity conservation and recreational opportunities. Ignoring these can lead to underestimations of WTP.
• Information Provision: The level of detail provided to respondents about the PES program and its management plan varies, which can affect the accuracy and relevance of the WTP estimates.

Assessment of Existing CV-PES Studies

• Quality Issues: Many of the reviewed studies do not adequately describe the survey instruments, CV scenarios, or fieldwork methods, making it difficult to assess their quality.
• Limited Scope: Only a few studies examine WTA, and even fewer address institutional and scientific uncertainties in their design.
• Language and Publication: Almost half of the studies are in Spanish, and only a few have been published in refereed journals, suggesting a reliance on gray literature.

Conclusion

The paper concludes that while CV-PES studies are a valuable tool for designing PES programs, their quality and usefulness can be significantly improved with minimal additional cost. This includes better methodological design, addressing uncertainty, and providing more comprehensive information to respondents. Improving these aspects will enhance the reliability and policy relevance of CV-PES studies.