[ajross]

> My house is valuable to me even if there isn't a collective belief in it.

It surely is, but this is just a semantic play on the word "value". You mean something like "personally important" in that sentence, the comment you were replying to was using it under its well-established economic definition.

In fact, your house is *not* valuable (in the economic sense) if there isn't a collective belief in it's equivalent in currency. Rather: it is exactly as valuable as the market is willing to pay, which is just a statement of the definition of "market value". That's what "collective belief" means in this context.