Policy Targeting under Network Interference
It addresses policy targeting in networks for researchers and practitioners, offering a practical solution without requiring full network information, but it is incremental as it builds on existing welfare optimization frameworks.
The paper tackles the problem of optimally allocating treatments under spillover effects by introducing a method that maximizes average social welfare using semi-parametric estimators and mixed-integer linear programming, with strong regret guarantees and application to social network information targeting.
This paper studies the problem of optimally allocating treatments in the presence of spillover effects, using information from a (quasi-)experiment. I introduce a method that maximizes the sample analog of average social welfare when spillovers occur. I construct semi-parametric welfare estimators with known and unknown propensity scores and cast the optimization problem into a mixed-integer linear program, which can be solved using off-the-shelf algorithms. I derive a strong set of guarantees on regret, i.e., the difference between the maximum attainable welfare and the welfare evaluated at the estimated policy. The proposed method presents attractive features for applications: (i) it does not require network information of the target population; (ii) it exploits heterogeneity in treatment effects for targeting individuals; (iii) it does not rely on the correct specification of a particular structural model; and (iv) it accommodates constraints on the policy function. An application for targeting information on social networks illustrates the advantages of the method.