We develop a framework to conduct experiments for estimating direct and spillover effects when units are grouped into mutually exclusive clusters. Crucially, our framework accounts for heterogeneous treatment effects across clusters and heterogeneous cluster sizes, which are pervasive in...

We set up a framework to conduct experiments for estimating spillover effects when units are grouped into mutually exclusive clusters. We improve upon existing methods by allowing for heteroskedasticity, intra-cluster correlation and cluster size heterogeneity, which are typically ignored when...