Tag Archives: Reader Comments

Covariate Contradiction?

Thoughtful reader Nikhil from UBC asks: I had a question regarding LATE. In your book you say in a model with covariates, 2SLS leads to a sort of "covariate averaged LATE" even when one does not have a saturated model. Does this mean that as one introduces covariates the 2SLS estimator is most likely to […]
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Why are There So Many Dummies?

Lina from Essex writes: When talking about grouped data and 2SLS (section 4.1.3) you mention that expanding a continuous instrument is equivalent to have a set of Wald estimators that consistent estimates the causal effect of interest and in the Vietnam paper you mention that using the whole set of dummies as instruments is more […]
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Regression what?!

Matt from Western Kentucky U comments on Chapter 3. . . Question: You state: “Our view is that regression can be motivated as a particular sort of weighted matching estimator, and therefore the differences between regression and matching estimates are unlikely to be of major empirical importance” (Chapter 3 p. 70) I take this to […]
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High Fashion at the Spring Meeting of Young Economists

as seen at the University of Groningen . . .what a good-lookin crew! what are they spelling?  I wish I knew
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good eye!

Hui Cao from China caught this one . . . and it’s in the “corrected printing” to boot! On 6/21/11 12:44 PM, 晖 曹 wrote: On page 75:  [p(Xi=x|Di=1)(1-p(Xi=x|Di=1)] should be [p(Di=1|Xi=x)(1-P(Di=1|Xi=x)} Yes indeed!
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MHE at 12000 feet

Andrea Ichino takes the RD message to new heights (specifically, to Cime Nere in Italian, as Andrea would like it; Hintere Schwarze in German – the peak straddles the Italian-Austrian border 3624m)
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Twin Econometricians!

Here’s a pair of the cutest econometricians we have ever seen, helpin’ their mama (Daniela Vuri) run regressions every day
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Lagged Dependent Variables with Random Effects

Henrik Lindemann would like to come back to our advice not to use fixed effects and a lagged dependent variable at the same time (see chapter 5.3/5.4 as well as your blog entry of October 6, 2009). Is it possible to use at least a random effects model in case I decide to use the […]
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ex post T and C for DD

Mel asks: Question: My understanding of a difference in difference model is that the two groups should exist before a policy takes affect (e.g. two states, companies, school districts). I was studying the impact of a policy on an outcome where the two groups did not exist until the policy went into effect and everyone […]
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The t and the p for just-ID will never surprise thee

My people always say that before embarking on a difficult empirical project.  A free t-shirt to the first poster who translates. JA
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