What changed
A parallel measurement world grew up next to evaluation, largely without evaluators. Between 2016 and 2021 the Impact Management Project convened more than two thousand practitioners around the "five dimensions of impact" (what, who, how much, contribution, risk) and the ABC classification (avoid harm, benefit stakeholders, contribute to solutions); stewardship of these norms passed to Impact Frontiers in 2021, which launched impact performance reporting norms in 2025.
GIIN's IRIS+ became the default metrics catalogue, IFC's Operating Principles for Impact Management (2019) created a verification regime, Social Value International completed standards for the principles of social value (the SROI lineage) and Harvard's Impact-Weighted Accounts tried to monetise impact into financial statements.
The EU's Corporate Sustainability Reporting Directive (in force 2023, with its "double materiality" test) and the ISSB standards pulled impact measurement into mainstream corporate reporting, followed by the 2025–26 "omnibus" simplification. Outcomes-based contracting and social impact bonds were tested, evaluated and found to rest on a thin, insider-dominated evidence base.
And philanthropy ran its own revolution: the Trust-Based Philanthropy Project (2020), MacKenzie Scott's multi-billion unrestricted and near-reportless gifts (studied over three years by the Center for Effective Philanthropy) and the "constituent voice" movement (Feedback Labs, Listen4Good) challenged the reporting apparatus that funders had built.
Frameworks and tools
- IMP five dimensions and ABC
- IRIS+
- Operating Principles for Impact Management
- Social Value International standards
- impact-weighted accounts
- CSRD/ESRS and ISSB
- outcomes-based contracting and impact bonds
- trust-based philanthropy's six practices
- feedback and constituent-voice tools
- Nesta, NPC and Bond evidence principles for NGOs
Vocabulary to recognise
- IMM (impact measurement and management)
- additionality
- impact risk
- double materiality
- impact washing
- outcomes-based contracting
- learning partner
- trust-based
- constituent voice
- proportionate evidence
Live controversies
Impact washing; the weak evidence for impact bonds (Fraser and colleagues' 2018 review; the Government Outcomes Lab's finding that only eleven of more than 450 studies on health impact bonds actually evaluated them); the tension between rigorous evaluation and trust-based learning (is it a real dichotomy?); the evaluation profession's uneasy relationship with the impact-investing world (Vo and Christie, 2018); and Itad's finding that most foundations evaluate but few use the results.
Further reading
- Impact Frontiers, Impact Management Norms and Five Dimensions of Impact.
- GIIN, The State of Impact Measurement and Management Practice, Second Edition, 2020; Operating Principles for Impact Management, The 9 Principles.
- Social Value International, Principles of Social Value; Harvard Business School, Impact-Weighted Accounts.
- UNEP FI, European Sustainability Reporting Standards (ESRS) explainer; Impact Management Platform, About.
- Anne Vo and Christina Christie, Where Impact Measurement Meets Evaluation: Tensions, Challenges, and Opportunities, American Journal of Evaluation, 2018.
- Alec Fraser, Stefanie Tan, Mylene Lagarde and Nicholas Mays, Narratives of Promise, Narratives of Caution: A Review of the Literature on Social Impact Bonds, Social Policy & Administration, 2018; Government Outcomes Lab, Show me the receipts! Evaluating the cost-effectiveness of impact bonds, 2019.
- Trust-Based Philanthropy Project, What is trust-based philanthropy?; Chera Reid and Shaady Salehi, Toward a Trust-Based Framework for Learning and Evaluation, Center for Evaluation Innovation, 2022.
- Center for Effective Philanthropy, Breaking the Mold: The effects of MacKenzie Scott's large, unrestricted gifts, year three, 2025, and Rigorous Evaluation Versus Trust-Based Learning: Is This a Valid Dichotomy?.
- Loïc Watine and Lucy Rimmington, Learning in Stages, Stanford Social Innovation Review, 2025.
- Rob Lloyd and Melanie Punton, Evaluating evaluations: When should philanthropy evaluate (and when shouldn't it)?, Alliance, 2023.
- Katie Smith Milway, Funding Feedback, Stanford Social Innovation Review, 2018; Feedback Labs, Feedback resources.
- NPC, The Code of Good Impact Practice; Bond, Evidence Principles.