[jgautsch]

Some economists would argue that "zillions of IOUs" is basically the precursor to currency/money. Then you just need a consistent unit, and that ability to trade/transact (which is a solved problem).

> Graeber proposes that money as a unit of account was invented the moment when the unquantifiable obligation "I owe you one" transformed into the quantifiable notion of "I owe you one unit of something". In this view, money emerged first as credit and only later acquired the functions of a medium of exchange and a store of value. [1]

[1] https://en.wikipedia.org/wiki/History_of_money