[simonh]

The value of a thing is in two parts, it's use value to it's possessor and it's exchange value with others.

Examples have already been posted here. My house has a use value to me because I need somewhere to live. If I lived on a small island off Antarctica it would still have great value to me but perhaps no value to anyone else.

Money is a financial instrument that only has exchange value, unless you count say the use of bank notes for lighting fires or papering walls. It's value as money is entirely by consensus.

Notably not even the government that issues it actually sets it's value. Ask the governments of Venezuela or Zimbabew about that. Yes of course they can do things that affect it's value, like printing too much of it or defaulting on bonds, or consistently paying on their bonds, but the actual value is set by people. When someone sells a product or service they ask for a price, and if someone pays it then that establishes a value for the product relative to other products, and a value for the currency exchanged. What happened in Zimbabwe is people asked for an awful lot of ZB$ for things compared to how many US$ they asked for. Thats what set the value of the ZB$ (and to some extent the US$ of course).

Governments sometimes do try to manipulate currency values through currency controls, but what that actually does is constrain currency flows. If a currency control set a high price for a currency, it will just not be traded as much, only people willing to pay the premium will do so. Those not willing to pay it simply won't and those transactions and that economic activity will be constrained (or the exchange will happen on the black market).

There can be coercive pressure of course, such as Russia requiring companies to hold Rubles, but you could hold a gun to my head and force me to hand over my house at a discount or for nothing. That says more about the use value of loaded guns than about the exchange value of my house. Governments have the ability to take value rather than exchanging it, but even that has it's limits.

[jmyeet]

It's true that utility is also a factor but it's extremely limited.

The house you and others have mentioned is an easy one. That whole concept of ownership is reliant on an entire system existing and enforcing those "rights". It's the threat of violence that prevents someone from showing up, "claiming" your house and kicking you out.

[simonh]

True, economically speaking personal use value doesn't really matter. It's great for you, but economics is about exchange.

Enforcement is an interesting factor. Laws can guarantee rights to enable and protect free exchange, but they can also coerce behaviour as I touched on.

In more or less free markets what laws do is provide guarantees that increase trust, which has the main effect of reducing costs. You don't need to personally audit the books of a company you invest in, because the government mandates that it's done for you to a set of standards which eliminates some risks (not all, just some). You don't need to personally research if the products you buy are safe or of a basic level of quality if the government mandates standards and enforces them, and if you have a right to return goods if you find a problem with them. This makes the goods themselves a little more expensive, but the overall costs and risks (which translates into costs) to consumers are much lower.