impact statement, definition 102
impacts see costs and benefits; risks
imperfect information 52
inflation 25-6
information 52
see also data
information asymmetry 52, 101, 102
information management and control 9
injuries 61-2
Integrated Policy Appraisal (IPA) 6, 6n
internal rate of return (IRR) 39, 39n, 102
international development assistance projects 99
intervention, rationale for 4, 11-12, 26, 51-6
irreversibility, definition 103
irreversible decisions 81
irreversible risk 88