The methods of economic appraisal are rooted in welfare economics and are well established in theory and in practice, around the world and across a huge range of applications.

Economic appraisal methods are used to inform decisions about proposed new policies and regulations, to help determine the impact of the policy, the form in which the policy or regulation should best be implemented, and whether or not it should be implemented at all. Economic appraisals are often at the heart of business plans, where companies need to justify their resulting business plans to their regulator(s).