The Green Book: Appraisal and Evaluation in Central Government
London, 2003
Abstract
The Green Book, a guide for appraising and evaluating public spending, has been updated to encourage a more thorough, long-term, and analytically robust approach. This edition emphasizes identifying, managing, and realizing benefits from the outset, focusing on achieving desired outcomes. The discount rate has been “unbundled,” introducing a 3.5% real rate based on social time preference and incorporating adjustments to address historical optimism bias. The Green Book also emphasizes assessing the differential impacts of proposals on different societal groups. This updated guidance is the result of a consultation process that ensured clarity and relevance for users. The Treasury acknowledges the contributions of many individuals across government and beyond in shaping this edition, particularly those who participated in the consultation.