The ruble and the fiscal theory of money

John Cochrane writes:

Facts

1. Oil prices have gone down by half. Russia is a big exporter, and the Russian government gets a lot of revenue from oil exports, 45% by one media account.

2. The Ruble is collapsing.

There is more to the argument than that, but that is not such a bad start.  The problem I have with the fiscal theory of money is that I do not know how to define the fundamental value of money.  It may work analytically to treat money as a “get out of jail card” of a defined value, yet it seems doubtful to me that is the only factor pinning down money’s value.  Multiple equilibria are running around in the background somewhere…we just don’t quite know how and where.