exchangeability

Exchangeability and value are different characteristics of goods.

But the theory of exchangeability is a separate matter, and cannot be deduced from the theory of value alone.

It is due Menger to point out that he does not make the distinction between value and exchangeability which I have just made.

Cf. also Amasa Walker's contention that "exchangeable value" is tautology, equivalent to "exchangeable exchangeability!"

The former means exchangeability; the latter means force of gravity.