I guess you didn’t read the article. A quick search shows she mentions it 8 times. Here are just a few: > We can define currency as a liability of an instituti

I guess you didn’t read the article. A quick search shows she mentions it 8 times. Here are just a few: > We can define currency as a liability of an institution, typically either a commercial bank or a central bank, that is used as a medium of exchange and unit of account. > Central Asians at the time of Battuta, as a nomadic culture, used livestock as money. The unit of account was a sheep, and larger types of livestock would be worth a certain multiple of sheep. > Prices of most things stay relatively stable or preferably keep going down as priced in the most salable good (such as gold, historically) over the long run, but go up in most years when measured in a depreciating and weaker unit of account such as the British pound.