Some time ago, Haynes Goddard emailed me suggesting that I post something about step-wise regression. He also put me on an interesting paper by Peter Flom and David Cassell.Many statistical and econometrics packages include stepwise regression. I wish ...
In a post last year I discussed the conditions under which the "adjusted" coefficient of determination (RA2) will increase or decrease, when regressors are deleted from (added to) a regression model. Without going over the full discussion again, h...
It is well known that dropping the constant in regression analysis may introduce bias. However, bias is really not the deeper issue. The deeper issue is that by omitting the constant, you are specifying a very specific form for the relationship b...
Students are told that if you're going to go in for sequential testing, when determining the specification of a model, then the sequence that you follow should be "from the general to the specific". That is, you should start off with a "large" model, a...
I always tell my students that, when it comes to regression results, the value of the coefficient of determination (R2), is pretty much the last thing that I look at. And I'm serious! I've blogged about this before (see here, for example), but it's wor...
Ordinary least squares continues to be the staple estimator for causal inference for good reason. In order to help new and veteran OLS users get a better sense of how it is working I have created a shiny app that allows for instant interactivity ...
