Privacy-Preserving Randomized Controlled Trials

Randomized Controlled Trials, when feasible, give the strongest and most trustworthy empirical measures of causal effects. They are the gold standard in many clinical, social, and behavioral fields of study. However, the most important settings often involve the most sensitive data, therefore cause privacy concerns. In this paper, we outline a way to deploy an end-to-end privacy-preserving protocol for learning causal effects from Randomized Controlled Trials (RCTs). We are particularly focused on the difficult and important case where one party determines which treatment an individual receives, and another party measures outcomes on individuals, and these parties do not want to leak any of their information to each other, but still want to collectively learn a true causal effect in the world. Moreover, we show how such a protocol can be scaled to 500 million rows of data and more than a billion gates. We also offer an open source deployment of this protocol.