Heckman: a myth debunker

In a recent paper in Sociological Methodology, James Heckman refers to "the myth that causality can only be determined by randomization, and that glorifies randomization as the ‘‘gold standard’’ of causal inference."

Heckman's article is a response to this article by Michael Sobel, who argues that Heckman's methods are actually not so different from the methods commonly used in statistics.