Impact investing — the deployment of private capital to produce both financial return and social impact — has grown rapidly. Whether it is producing impact at the scale its growth suggests is a different question.
What Impact Investing Claims
Impact investing — the deployment of private capital in ways that are intended to produce both financial return and measurable social or environmental impact — has grown from a niche practice into a mainstream institutional phenomenon. The claim that it represents is significant: that the capital markets, properly structured, can address social and environmental challenges at the scale that public finance and philanthropy cannot reach, by deploying private capital in ways that produce social impact alongside financial return.
This claim is contested in a specific and important way. The impact investing field has not yet produced the rigorous evidence base that would allow confident assessment of whether the social impacts claimed are genuinely additional — whether they would have occurred without the impact investment, or whether the impact label is being applied to investments that would have produced their outcomes regardless of whether they were structured as impact investments.
The Additionality Problem
The additionality problem — the challenge of demonstrating that the impact attributed to impact investing would not have occurred without it — is the central unresolved challenge of the field. Without additionality, impact investing is standard investing with impact measurement attached — producing the financial returns that standard investing produces and the social outcomes that the underlying business or project would have produced anyway, without any additional social value from the impact investing structure.
Impact investing's promise is that private capital can do what public capital cannot do enough of. The evidence for this promise requires demonstrating additionality — that the impact is genuinely produced by the investment structure rather than by the underlying activity that would have happened regardless. The field has grown faster than that evidence base.
Discussion