Testing for arbitrary interference on experimentation platforms

Understand

Experimentation platforms are essential to modern large technology companies, as they are used to carry out many randomized experiments daily.

• The classic assumption of no interference among users, under which the outcome of one user does not depend on the treatment assigned to other users, is rarely tenable on such platforms.
• Here, we introduce an experimental design strategy for testing whether this assumption holds.
• Our approach is in the spirit of the Durbin-Wu-Hausman test for endogeneity in econometrics, where multiple estimators return the same estimate if and only if the null hypothesis holds.