additionality

noun ! Definition from Wiktionary (CC BY-SA). More about additionality at Wordnik → Where our words come from →

1. The property of being additional.
2. Net positive difference that results from economic development intervention. The extent to which an activity (and associated outputs, outcomes and impacts) is larger in scale, at a higher quality, takes place quicker, takes place at a different location, or takes place at all as a result of intervention. Additionality measures the net result, taking account of deadweight, leakage, displacement, substitution and economic multipliers.