Multicollinearity

In fact, if they're correlated, statistics professors kind of freak out and they give it this big long name.

Do you remember what that was? Multicollinearity.

I remember hearing, who the hell cares? Now I know why you should care, because when the variables start to be correlated with each other, remember, what does a computer see when you put these four columns? It doesn't see growth and level.

It just sees four sets of numbers.