On the Interpretation of do(x)

Abstract

This paper provides empirical interpretation of the d o ( x )do(x) operator when applied to non-manipulable variables such as race, obesity, or cholesterol level. We view d o ( x )do(x) as an ideal intervention that provides valuable information on the effects of manipulable variables and is thus empirically testable. We draw parallels between this interpretation and ways of enabling machines to learn effects of untried actions from those tried. We end with the conclusion that researchers need not distinguish manipulable from non-manipulable variables; both types are equally eligible to receive the d o ( x )do(x) operator and to produce useful information for decision makers.