What Is the Exchange Rate between Cattle and Cocoa Beans?

With Oathbreaker in the capable hands of my beta team, I’ve been doing a bit of worldbuilding for another project that’s kicking around in my head.

Unlike the cashless society of the Wonder, I’ve been pondering a world that uses some sort of commodity currency as a medium of exchange. In the process, I’ve found a few interesting options. Here are some random notes about three of them.

Irish Cattle

The Irish used cattle as a unit of exchange up until the fourteenth century. Specifically, the milk cow was universally recognized measure of worth. There were even ways to achieve fractions of that value without killing the cow. In medieval Ireland,

1 pregnant cow = 2/3 of a milk cow
1 three-year old heifer = 1/2 of a milk cow
1 two-year old heifer = 1/3 of a milk cow
1 one-year old heifer = 1/4 of a milk cow
1 one-year old bullock = 1/8 of a milk cow

Worth in milk cows could also be expressed in terms of other currencies such as “ounces” of some precious metal (usually silver), cumhala or “bondwomen” (i.e., female slaves), or séti or “jewels.” The sét seems to have been an ideal or an abstraction in Irish law, and it is not clear that transactions were ever literally conducted by the transfer of female slaves from one person to another. Still, everyone had a clear idea of what these things were worth and conducted their business accordingly.

Unfortunately, this system persisted for so long that the law codes prescribed different rates of exchange in different eras and in different regions of Ireland. A cumhal might be the same value as a milk cow or it might be two or three times as much. One source gives the value of a cumhal as two séti, another says six to seven, and yet another says up to forty.

Since 240 English pence were struck from a pound of silver, we can assume that an ounce of silver would be worth about 15 pence. At a rate of 1 milk cow = 9 ounces of silver, the price of a milk cow in silver would be about 135 pence, which is in line with some of the early medieval prices I’ve been able to find online—and, incidentally, very close to the price of 131.5 pence given for a female slave in this era.

Mexican Cocoa Beans

When the Spanish arrived in Mexico, they found a society in which cocoa beans were an accepted medium of exchange. Some of the customary prices I’ve found are:

a large tomato for 1 cocoa bean
a small rabbit for 30 cocoa beans
a female turkey for 100 cocoa beans
a male turkey for 300 cocoa beans
a copper hatchet for 8,000 cocoa beans

The Spanish adapted this system in dealing with the Aztecs. In fact, cultivation of cocoa beans was restricted in the 1700s in order to maintain their value as money.

By a royal decree of 1555, the value of one cocoa bean was set at 1/140 of a Spanish real. In 1587, this was dropped to 1/150 of a real. Since a peso or “piece of eight” was worth eight reales, we could also say that 1,200 cocoa beans = 1 peso. In the mid-sixteenth century, pesos traded in England at about 54 pence. Once again, that makes the commodity prices reasonable when compared to equivalent items in the same time frame.

Canadian Beaver Pelts

The Hudson Bay Company in Canada was a key player in the North American fur trade. Not only did their stores buy furs brought in by traders, they accepted furs as currency. The above linked article even provides a price list for the York factory in units of “made beaver” (i.e., a prime beaver pelt). Here is a selection of prices:

a hatchet for 1 beaver pelt
a pound of tobacco for 2 beaver pelts
a pair of shoes for 3 beaver pelts
a hat for 4 beaver pelts
a pistol for 7 beaver pelts
a long gun for 14 beaver pelts

In 1740, the Hudson Bay Company bought beaver pelts for about 7.88 shillings apiece (about 94.5 pence). But assessing the exchange rate isn’t that simple. In fact, the Company store customarily marked up their prices by about 50%. That means your 94.5 pence worth of beaver pelt would only buy you goods that cost 63 pence in silver at a different establishment.

And no, I have no intentions of writing a protagonist who works as a bank teller or a merchant at a company store! But I find that little touches like these add a depth of detail that can really make a setting seem real.

Plus, I’ve learned a few things along the way, and no new knowledge is ever a waste of time.