It was exciting to read the new working paper Addressing attribution of cause and effect in small n impact evaluations: towards an integrated framework by Howard White and Daniel Phillips. While it would be ideal that all the interventions we design would have the number of participants (n) and impact that would give us a statistically significant result at a high level of confidence, there are many reasons that this doesn’t happen. For payment-by-results contracts, in particular social impact bonds, attributing an impact to an intervention is a pre-requisite for the transfer of public funds. Also, funders the world over are attempting to identify the impact they are making across their portfolios, to increase the effectiveness of their investments. White and Phillips produce a fantastic summary of methods and examples that seek to attribute change to a cause. While their framework of small n methods is useful, it’s their up-to-date literature review that I find most useful.
The paper is published by 3ie: International Initiative for Impact Evaluation. 3ie have developed a database of policy briefs, impact evaluations and systematic reviews. They’re governed and staffed by a trans-global team, and while focussed on international development, their evaluation work is certainly relevant for interventions that alleviate disadvantage at a local or national level.