This paper reflects on a recent article by Heckman and Pinto (2013) in which they discuss a formal system, called do-calculus, that operationalizes Haavelmo's conception of policy intervention. They replace the do-operator with an equivalent operator called 'fix,' highlight the capabilities of 'fix,' discover limitations in 'do,' and inform readers that those limitations disappear in 'the Haavelmo approach.' I examine the logic of HP's paper, its factual basis, and its impact on econometric research and education.
展开▼
