I believe Von Neumann showed that any consistent ordinal utility can be mapped to a cardinal utility. As long as you can rank your preferences, for cats, childr

I believe Von Neumann showed that any consistent ordinal utility can be mapped to a cardinal utility. As long as you can rank your preferences, for cats, children, or whatever, you can come up with an equivalent cardinal utility. So I think Waldman's statement is technically correct, the two are equivalent, and one isn't more scientific than the other. There is this notion that it's bad form to say, a rich person gets less marginal utility out of a dollar than a poor person, or sum up utilities across people. And it's bad form to quantify the value of a human life for instance. You can, however, say the rich person values leisure at more dollars than the poor person. If you could sum up utilities across people I'm sure it would lead one to very bad conclusions, unlike some of the other simplifications economists make, which only lead to useful conclusions. <cough> Actually, I'm not really certain what it would change, if anything. In any event it would appear that humans aren't very consistent with their preferences, c.f. behavioral economics, hence the notion of utility may lead one astray whether one views it as an ordinal ranking or cardinal quantity.