Additionality

Additionality is the property of an activity being additional by adding something new to the context. It is a determination of whether an intervention has an effect when compared to a baseline. Interventions can take a variety of forms but often include economic incentives. Additionality may be evaluated ex post, as is often done in the practice of program evaluation, or ex ante, as an initial eligibility screen for issuing credits as part of an environmental or other public goods market.

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