I'd say they're correlated, which is part of the reason the fallacy arises. But the coefficient is different for every customer, so unless you're in a market wi

I'd say they're correlated, which is part of the reason the fallacy arises. But the coefficient is different for every customer, so unless you're in a market with homogeneous buyers, any segmentation you devise is very likely to be wrong for almost everyone. See my longer answer nearby for some pathological examples.