A natural question: When the qualitative variable takes k categorical values, why don't we simply encode it with k "yes/no" variables? Conceptually, this would work. Practically, it fails inside the ...

AirEntrain is a categorical (yes/no) variable and cannot be used in regression without transforming it to a numerical {0,1} dummy/indicator variable. We can use our recoding skills from Lesson 5 to do ...

Indeed, many commercially-available regression-analysis packages contain specific features to facilitate the construction of new variables (i.e., new columns of data) from products of existing ...

Conditions are established conditions under which it is possible to identify the average effect of the dummy endogenous regressor in a weakly separable model without relying on parametric functional ...