Judea Pearl has a new book (with Dana Mackenzie).
amazon.com/Book-Why-Scien…
To me, Judea is an intellectual hero. My life changed after hearing him at Harvard over 20 years ago. Like many of us in #causalinference, I owe so much to him.
And yet I disagree with him on a key issue.
amazon.com/Book-Why-Scien…
To me, Judea is an intellectual hero. My life changed after hearing him at Harvard over 20 years ago. Like many of us in #causalinference, I owe so much to him.
And yet I disagree with him on a key issue.
Pearl believes that any causal effect we can name must also exist.
To him, the meaning of “the causal effect of A on death” is self-evident. He says we can quantify, say, the causal effect of race or the causal effect of obesity.
I don't think we can.
To him, the meaning of “the causal effect of A on death” is self-evident. He says we can quantify, say, the causal effect of race or the causal effect of obesity.
I don't think we can.
We cannot estimate "the causal effect of obesity" because we don't know what that means.
For the causal effect of A to be well defined, we need a common understanding of the interventions that we would use to change A. Otherwise, the effect is undefined.
ncbi.nlm.nih.gov/pmc/articles/P…
For the causal effect of A to be well defined, we need a common understanding of the interventions that we would use to change A. Otherwise, the effect is undefined.
ncbi.nlm.nih.gov/pmc/articles/P…
To define a causal effect, describe the hypothetical randomized experiment that you'd conduct to quantify the effect. If you can't describe the experiment (#TargetTrial), chances are you don't know what causal effect you are after.
My view, not Pearl's.
academic.oup.com/aje/article/18…
My view, not Pearl's.
academic.oup.com/aje/article/18…
If by now you are thinking that this is just another academic debate on the sex of the angels, think again: you beliefs about this issue determine your beliefs about the limits of science and about how to conduct data analyses.
Also, get Pearl's book.
Also, get Pearl's book.
Judea Pearl is not on Twitter so I emailed him this thread and offered to tweet his reply. He wrote back and asked me to post this:
