Why are RCTs the Gold Standard? The Epistemological Difference Between Randomized Experiments and Observational Studies.

Abstract

In response to Pearl, Aronow et al. (2025) argue that randomized experiments are special among causal inference methods due to their statistical properties. I believe that the key distinction between randomized experiments and observational studies is not statistical, but rather epistemological in nature. In this comment, I aim to articulate this epistemological distinction and argue that it ought to take a more central role in these discussions.