Policy design in experiments with unknown interference

Understand

This paper studies experimental designs for estimation and inference on policies with spillover effects.

• Units are organized into a finite number of large clusters and interact in unknown ways within each cluster.
• First, we introduce a single-wave experiment that, by varying the randomization across cluster pairs, estimates the marginal effect of a change in treatment probabilities, taking spillover effects into account.
• Using the marginal effect, we propose a test for policy optimality.