What is a co-funding affinity?

Co-funding affinity

How much two funders overlap relative to what their sizes alone would predict.

Two large funders will share recipients simply because they both make many grants, so a raw count of shared organizations mostly measures size. Affinity compares the observed overlap against what size alone predicts, which is what makes a genuine relationship visible.

The estimate is a Gamma-Poisson posterior rate re-centered on the typical rate. In plain terms, a pair with very little evidence behind it is pulled toward no signal rather than being allowed to look like a strong tie on the strength of one or two shared grants. This is empirical-Bayes shrinkage, and it is why a thin pair does not top the rankings.

See it in the data

The funder camps

Questions and answers

What is a co-funding affinity?: How much two funders overlap relative to what their sizes alone would predict. Two large funders will share recipients simply because they both make many grants, so a raw count of shared organizations mostly measures size. Affinity compares the observed overlap against what size alone predicts, which is what makes a genuine relationship visible.