A framework and a tool for comparing grants when the evidence cannot settle which is better.
Built by the Founders Pledge climate research team for our own grantmaking. Written for researchers and grantmakers; free to use.
Why does it matter?
Compare it to the gold standard. Direct-delivery global health has randomised evidence, and you know fairly closely how that evidence applies. Model uncertainty is low.
Now think about climate. Building a neglected energy technology directly is not very cost-effective. Advocate for a government to deploy it instead and you probably do better — but no one knows how much better. Advocate for innovation policy rather than for the technology, and you have added another uncertainty on top. It becomes an almost meaningless question whether something meets the bar. And that is essentially every field we care about, apart from this one.
The approach
So we stopped asking whether one grant meets the bar. We keep the uncertainty instead of collapsing it: every input is a distribution, and the whole set of grants is simulated together rather than one at a time.
We then compare portfolios rather than grants. Each is scored across all ten thousand worlds, so the one worth choosing is the one that holds up everywhere — not the one that wins most often.
Describe the grants and the uncertainties that separate them. Each grant leverages its own subset.
Draw every uncertainty ten thousand times. Each grant's cost-effectiveness becomes a distribution, not a number.
Identify the portfolios that perform best across all ten thousand worlds at once.
Because the model knows which uncertainties changed the allocation, it also knows which ones are worth researching. Some assumptions you spend a long time on never change a decision; others turn out to decide it. That makes this as much a way of choosing what to research as what to fund.
Worked examples
These are teaching examples, deliberately simplified — not records of grants we have made.
We have not solved this. The Impact Model is a research project of the Founders Pledge climate team, and if you make grants under deep uncertainty we would like to hear from you.