David Liu comments in regards to "Robustness of Causal Claims" :
It was said in the paper that: "if the two estimates of b happen to disagree in a specific study, we can conclude that the disagreement must originates with violation of those extra assumptions that are needed for the second, and we can safely discard the second in favor of the first." But, if the first (minimal assumptions set) is false, then the two estimates of b may disagree too. So we can only conclude that the first or the second is false.
Clark Glymour writes:
Nancy Cartwright devotes half of her new book, Hunting Causes and Using Them, to criticizing "Bayes Net Methods"–as she calls them–and what she takes to be their assumptions. All of her critical claims are false or at best fractionally true. This paper reviews the literature she addresses but appears not to have met. Please click here to read further.
For related discussion, please see a previous post by Judea Pearl.
David Judkins writes:
I just saw Dylan Small give a very interesting talk in Salt Lake City on mediation analysis using random assignment interacted with baseline covariates as instrumental variables. He mentioned that Albert (2007) just established a formal definition for mediated effects with Neyman-Rubin causal language. Anyone know which Albert? Is it James Albert at Bowling Green? Any rival formal definitions for mediated effects? Page 165 of Pearl's 2000 text has a definition of indirect effects, but I didn't find it quite as satisfying as the version that Small put on the screen last week.
Judea Pearl writes:
A new book on causality came out last month, Hunting Causes and Using Them by Nancy Cartwright (Cambridge University Press, 2007.) Cartwright is a renown philosopher of science who has given much thought to the methodology of econometrics, and I was keenly curious to read her take on the current state of causality in economics.
Cartwright summarizes what economists such as Heckman, Hoover, Leroy and Hendry said and wrote about causal analysis in economics, she occasionally criticizes their ideas, and further discusses related works by philosophers such as Hausman and Woodward, but what I found surprising is that she rarely tells us how WE OUGHT to think about causes and effects in economic models. Given that economists admit to the chaotic state of affairs in their court, the role of philosophy should be, in my opinion, to instill clarity and provide coherent unification of the field. This I could not find in the book.
Additionally, and this naturally is my main concern, Cartwright rejects the surgery method as the basis of counterfactual and causal analysis and, in so doing, unveils and reinforces some of the most serious misconceptions that have hindered causal analysis in the past half century (see my earlier posting on Heckman's articles.)
I will focus on the latter point, for this will illuminate others.
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Judea Pearl writes:
My previous posting in this forum raised questions regarding Jim Heckman's analysis of causal effects, as described in his article, "The Scientific Model of Causality" (Sociological Methodology, Vol. 35 (1) page 40.)
To help answer these questions, Professor Heckman was kind enough to send me a more recent paper entitled: "Econometric Evaluation of Social Programs," by Heckman and Vytlacil (Draft of Dec. 12, 2006. Prepared for The Handbook of Econometrics, Vol. VI, ed by J. Heckman and E. Leamer, North Holland, 2006.)
This paper indeed clarifies some of my questions, yet raises others. I will share with readers my current thoughts on Heckman's approach to causality and on where causality is heading in econometrics.
(Post edited 5/4: revisions in red, thanks to feedback from David Pattison)
(Post edited 5/17: correction and new comments by LeRoy and Pearl)
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