What would count as progress
Evidence from natural experiments or trials on how restriction affects outcomes, including the conditions under which each kind of funding works better.
Why it matters
The case for unrestricted funding is strong but mostly built on surveys of what charities prefer. A science of giving needs outcome evidence, including any cases where restriction does better.
Where to start
Large shifts toward unrestricted giving, such as funders that relaxed restrictions in 2020, are natural experiments. Comparing grantee outcomes before and after is a feasible first study.