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 ...

Regression uses qualitative variables to distinguish between populations ... He believes that the type of firm may affect this relationship and suspects that there may be some interaction between the ...

Because the model includes an intercept, no dummy variable is added for December. The December effect is measured by the intercept, while the effect of other seasons is measured by the difference ...