دانلود رایگان مقاله کاربرد روش دلفی برای ارزش حفاظت از جنگل های بارانی آمازون

Abstract

Valuing global environmental public goods can serve to mobilize international resources for their protection. While stated-preference valuation methods have been applied extensively to public goods valuation in individual countries, applications to global public goods with surveys in multiple countries are scarce due to complex and costly implementation. Benefit transfer is effectively infeasible when there are few existing studies valuing similar goods. The Delphi method, which relies on expert opinion, offers a third alternative. We explore this method for estimating the value of protecting the Amazon rainforest, by asking more than 200 environmental valuation experts from 37 countries on four continents to predict the outcome of a contingent valuation survey to elicit willingness-to-pay (WTP) for Amazon forest protection by their own countries' populations. The average annual per-household values of avoiding a 30% forest loss in the Amazon by 2050, assessed by experts, vary from a few dollars in low-income Asian countries, to a high near $100 in Canada, Germany and Norway. The elasticity with respect to average (PPP-adjusted) per-household incomes is close to unity. Results from the Delphi study match remarkably well those from a recent population stated-preference survey in Canada and the United States, using a similar valuation scenario.

4. Conclusions and Final Discussion

Our Delphi study was intended to serve several objectives. First, it provided an initial estimate of WTP to protect the Amazon for a large share of the global population. Second, the distribution of the experts' WTP predictions may help us construct more efficient experimental designs (Ferrini and Scarpa, 2007) for the actual stated-preference (SP) valuation studies on Amazon protection that we intend to undertake. In addition, as part of the Delphi study we sought the experts' guidance on various other aspects of the design of populationbased SP surveys involving Amazon protection plans where a key problem is that respondents may believe that if they pay to protect tropical forest for biodiversity purposes they must also be protecting the carbon from those forests from being released.3 Third, we ultimately seek to compare the WTP estimates from our Delphi study to estimates from actual population SP studies. A large discrepancy between the Delphi and SP estimates, either absolutely or relatively across the countries for which we will have estimates from both, may provide useful information for analyzing and refining both approaches. Finally, the Delphi study provides WTP estimates for many countries in which we do not have the resources to conduct SP studies. Depending on the results of the comparison just mentioned, we may be able to use these estimates to augment the SP-based estimates in terms of either absolute WTP levels or, perhaps more likely (León et al., 2003), relative WTP differences across the countries with SP-based estimates and those without.