It seems to be true that whatever is useful is valuable economically, but is the reverse true? What would it mean for something to be valuable but not useful? It seems that it would mean that a thing had value simple in existing. It is sought for no use, but simple that it be possessed and exist. This seems contrary to the very fundamental logic of human desire, but let us consider an example, collectibles.
Collectibles are the sort of thing that are accumulated for no other reason than to possess them. In fact, they are better qua collectible if they are not used for anything. They are bought and sold to be placed on shelves never to be used or touched. In fact there are things which have significant usefulness that are nevertheless collected in this way.
There are two ways that we might approach this. We may say that the accumulation of collectibles is irrational, because it is contrary to the logic of economics and wealth getting. That is, the collection of things for no purpose has no end, reason or logic.
However, it does not seem in general that this is the case. People use collectibles in a limited but still real way. The very act of collecting is using the things. For collectors this is often a source of joy, perverse or not. This is indeed a reason to collect, that it produce some pleasure or joy for the collector. The things having been collected may also be enjoyed to view as collections of art are enjoyable.
What we spoke of in the beginning was the mere storage of things for no purpose. This is the key that men accumulate things for some purpose. It is this purpose that brings to light the usefulness of the thing. It is also this purpose that can be judged against the objective standards of reality to determine if it uneconomic or in some way perverse. In this sense, it seems that everything that has economic value is useful and this is what we mean by economic value, that is a capacity to achieve men’s ends.