手法を比較

	Backcasting for Policy	Ex-Ante Policy Appraisal
分野	Public Policy	Public Policy
系統	Process / pipeline	Process / pipeline
提唱年	1990	2022
提唱者	John B. Robinson (building on Amory Lovins' energy work)	Public-finance appraisal tradition; codified by HM Treasury (Green Book)
種類	Normative futures and foresight method	Structured ex-ante appraisal of policy options
原典	Robinson, J. B. (1990). Futures under glass: A recipe for people who hate to predict. Futures, 22(8), 820–842.	HM Treasury (2022). The Green Book: Central Government Guidance on Appraisal and Evaluation. London: HM Treasury.
別名	Backcasting, Policy Backcasting, Normative Scenario Backcasting	Policy Appraisal, Options Appraisal, Green Book Appraisal
関連	4	4
概要	Backcasting is a normative futures method that starts from a desirable future end-state and works backward to determine the policies, actions and milestones needed to reach it from the present. Coined and developed by John Robinson, who set out its logic in his 1990 article 'Futures under glass', it deliberately contrasts with forecasting: rather than asking what future is likely given current trends, backcasting asks what future we want and how we could get there. It is especially suited to long-term, transformative challenges such as sustainability and decarbonisation, where prevailing trends point away from where society needs to go.	Ex-ante policy appraisal is the structured assessment of the costs, benefits, risks and trade-offs of alternative options for achieving a policy objective, carried out before a decision is taken. Codified in guidance such as the UK Treasury's Green Book, it provides a disciplined framework for deciding whether to intervene and, if so, how — by establishing the rationale and objectives, generating and narrowing a range of options, appraising each against a counterfactual, and recommending the option that offers best value for public money. Appraisal is the forward-looking complement to ex-post evaluation, which judges interventions after they have run.