Policy impact assessments, or simply impact assessments (IAs), are formal, evidence-based procedures that assess prospective economic, social, and environmental effects of a public policy proposal.[1] They have been incorporated into policy making in the OECD countries and the European Commission. If the assessment is favourable, and the proposed policy is enacted—after a suitable length of time for the policy to gain traction—it might be followed by an impact evaluation; ideally, assessed impacts before the fact and evaluated impacts after the fact are not wildly divergent. In some cases, impact becomes politicized due to a change in the governing regime between assessment and evaluation, and non-congruence might be amplified for ideological reasons. In other cases, the world is a complex place, and assessment is not a perfect art.
Key types of impact assessments include global assessments (global level), policy impact assessment (policy level), strategic environmental assessment (programme and plan level), and environmental impact assessment (project level). Impact assessments can focus on specific themes, such as social impact assessments and gender impact assessments.
IAs can improve legislation by:[2]