I've been reading "Modern Grantmaking: A Guide for Funders who believe better is possible" and it talks about the benefits of offering unrestricted funding. I found this interesting report written by IVAR on approaches to assessing the impact of unrestricted funding written in June 2024.
"Whether you are a funder who offers unrestricted funding, or a charity in receipt of it, the findings will speak to those who are looking for more equal and open relationships with funded organisations, and those who want to make informed judgements about their contribution to positive social change."
The report can be downloaded on the link below
Five Approaches to assessing the impact of unrestricted funding