Posts Tagged ‘ Causal Inference ’

Air rage update

September 22, 2017
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So. Marcus Crede, Carol Nickerson, and I published a letter in PPNAS criticizing the notorious “air rage” article. (Due to space limitations, our letter contained only a small subset of the many possible criticisms of that paper.) Our letter was called “Questionable association between front boarding and air rage.” The authors of the original paper, […] The post Air rage update appeared first on Statistical Modeling, Causal Inference, and Social…

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Causal inference using data from a non-representative sample

September 14, 2017
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Dan Gibbons writes: I have been looking at using synthetic control estimates for estimating the effects of healthcare policies, particularly because for say county-level data the nontreated comparison units one would use in say a difference-in-differences estimator or quantile DID estimator (if one didn’t want to use the mean) are not especially clear. However, given […] The post Causal inference using data from a non-representative sample appeared first on Statistical…

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“How conditioning on post-treatment variables can ruin your experiment and what to do about it”

September 12, 2017
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“How conditioning on post-treatment variables can ruin your experiment and what to do about it”

Brendan Nyhan writes: Thought this might be of interest – new paper with Jacob Montgomery and Michelle Torres, How conditioning on post-treatment variables can ruin your experiment and what to do about it. The post-treatment bias from dropout on Turk you just posted about is actually in my opinion a less severe problem than inadvertent […] The post “How conditioning on post-treatment variables can ruin your experiment and what to…

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Rosenbaum (1999): Choice as an Alternative to Control in Observational Studies

September 4, 2017
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Winston Lin wrote in a blog comment earlier this year: Paul Rosenbaum’s 1999 paper “Choice as an Alternative to Control in Observational Studies” is really thoughtful and well-written. The comments and rejoinder include an interesting exchange between Manski and Rosenbaum on external validity and the role of theories. And here it is. Rosenbaum begins: In […] The post Rosenbaum (1999): Choice as an Alternative to Control in Observational Studies appeared…

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Causal identification + observational study + multilevel model

September 1, 2017
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Sam Portnow writes: I am attempting to model the impact of tax benefits on children’s school readiness skills. Obviously, benefits themselves are biased, so I am trying to use the doubling of the maximum allowable additional child tax credit in 2003 to get an unbiased estimate of benefits. I was initially planning to attack this […] The post Causal identification + observational study + multilevel model appeared first on Statistical…

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What are best practices for observational studies?

August 30, 2017
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Mark Samuel Tuttle writes: Just returned from the annual meeting of the American Medical Informatics Association (AMIA); in attendance were many from Columbia. One subtext of conversations I had with the powers that be in the field is the LACK of Best Practices for Observational Studies. They all agree that however difficult they are that […] The post What are best practices for observational studies? appeared first on Statistical Modeling,…

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The Pandora Principle in statistics — and its malign converse, the ostrich

August 16, 2017
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The Pandora Principle is that once you’ve considered a possible interaction or bias or confounder, you can’t un-think it. The malign converse is when people realize this and then design their studies to avoid putting themselves in a position where they have to consider some potentially important factor. For example, suppose you’re considering some policy […] The post The Pandora Principle in statistics — and its malign converse, the ostrich…

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Torture talk: An uncontrolled experiment is still an experiment.

August 13, 2017
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Paul Alper points us to this horrifying op-ed by M. Gregg Bloche about scientific study of data from U.S. military torture programs. I’ll leave the torture stuff to the experts or this guy who you’ve probably heard of. Instead, I have a technical point to make. In the op-ed, Bloche writes: In a true experimental […] The post Torture talk: An uncontrolled experiment is still an experiment. appeared first on…

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Does declawing cause harm?

August 12, 2017
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Does declawing cause harm?

Alex Chernavsky writes: I discovered your blog through a mutual friend – the late Seth Roberts. I’m not a statistician. I’m a cat-loving IT guy who works for an animal shelter in Upstate New York. I have a dataset that consists of 17-years’-worth of animal admissions data. When an owner surrenders an animal to us, […] The post Does declawing cause harm? appeared first on Statistical Modeling, Causal Inference, and…

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It’s hard to know what to say about an observational comparison that doesn’t control for key differences between treatment and control groups, chili pepper edition

August 3, 2017
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Jonathan Falk points to this article and writes: Thoughts? I would have liked to have seen the data matched on age, rather than simply using age in a Cox regression, since I suspect that’s what really going on here. The non-chili eaters were much older, and I suspect that the failure to interact age, or […] The post It’s hard to know what to say about an observational comparison that…

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