Tag Archives: Reader Comments
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 [...]
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 [...]
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
Regression Is Matching (one more way; with discussion!)
Pat Kline has a nifty new interpretation of the old Blinder-Oaxaca regression estimator for two-group comparisons (in this case, applied to treatment effects in a selection-on-observables setup) . . . It’s a matching estimator, of course! Here’s the version we saw at ASSA in Denver, niftier than ever! and my discussion, which is pretty good [...]
Kindle KAOS
A few disappointed readers have commented that the kindle version of MHE suuu . . . is not so hot. Math font KAOS, Mr. Smart! (with type set by Shtarker, among other unforgivable glitches.) But ebook aficianados don’t dispair, just install one of Amazon’s free reading apps and read glitch-free on the hardware of your [...]
Corrections Coming!
Princeton University Press has graciously released a corrected version of MHE. This is not a new edition (we’re still recovering from the first!). But we’ve corrected the mistakes uncovered by careful readers in the past 18 months. The corrected version is now in print and should be shipping soon from Amazon and other big retailers. [...]
Possibly Harmful Econometrics?
Northwestern finance Prof Bernard Black describes some interesting causality bloopers, a valuable caution for students and teachers alike!
Regression anatomy revealed
Valerio Filoso from the University of Naples has written a neat Stata routine that automates the regression anatomy formula and makes a complete family of partial regression plots. Check it out!
Can I get an indulgence for bad control?
We get a lot of questions about bad control. Here’s an interesting one from Colin Vance: I'd like to estimate the effect of fuel price (which I assume is exogenous) on distance driven. As a control, I would like to include the fuel efficiency of the driver's car. Although efficiency is likely to be endogenous, [...]
Twin Econometricians!