Using the Delphi method to value protection of the Amazon rainforest

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.

Duke Scholars

Author Jeffrey R. Vincent Environmental Sciences and Policy