手法を比較

	Delphi Environmental Foresight	Deliberative Monetary Valuation
分野	Environmental Sociology	Environmental Economics
系統	Process / pipeline	Process / pipeline
提唱年	1999	2007
提唱者	Gene Rowe & George Wright (synthesizing the RAND Delphi tradition)	Clive L. Spash (and the deliberative-valuation tradition)
種類	Iterative anonymous expert-elicitation pipeline with controlled feedback	Deliberative pipeline combining group reasoning with monetary valuation
原典	Rowe, G., & Wright, G. (1999). The Delphi technique as a forecasting tool: issues and analysis. International Journal of Forecasting, 15(4), 353-375.	Spash, C. L. (2007). Deliberative monetary valuation (DMV): Issues in combining economic and political processes to value environmental change. Ecological Economics, 63(4), 690-699.
別名	Environmental Delphi, Policy Delphi, Delphi Expert Elicitation, Iterative Expert Consensus Survey	Deliberated Willingness to Pay, Group-Based Environmental Valuation, Citizens' Jury Valuation, Social Willingness to Pay
関連	3	3
概要	The Delphi method is a structured technique for aggregating expert judgment about uncertain or future-oriented questions through several rounds of anonymous, individually completed surveys with controlled feedback between rounds. As distilled in Rowe and Wright's 1999 analysis, its defining features are anonymity, iteration, controlled feedback of the group's responses, and statistical summary of the panel's collective view. Applied to environmental foresight, Delphi is used to elicit and synthesize expert opinion on questions where hard data are sparse or absent — the timing of ecological thresholds, the plausibility of emerging risks, the priority of research needs, or the likely effectiveness of policy options. By letting experts revise their judgments in light of the anonymized group response, Delphi seeks reasoned convergence while filtering out the social pressures of face-to-face committees.	Deliberative monetary valuation is a hybrid method that combines the deliberative processes of political theory with the monetary metric of environmental economics, eliciting willingness to pay for environmental change through structured group discussion rather than isolated individual survey responses. In Clive Spash's 2007 analysis, the approach responds to a central criticism of conventional stated-preference methods — that they assume people arrive with well-formed preferences and treat them as private consumers — by giving participants information, time, and the company of others with whom to reason before expressing a value. Deliberation can produce individual willingness-to-pay figures formed through discussion, or genuinely social values agreed by the group acting as citizens. Spash stresses that the resulting numbers can rest on very different ethical bases, from market exchange to fair prices to expressive or arbitrated social judgments, which complicates their interpretation as standard welfare measures.