In most ways […] we can treat rent and taxes together because their economic impacts are actually pretty similar: they force the farmer to farm more in order to supply some of his production to people who are not the farming household.

There are two major ways this can work: in kind and in coin and they have rather different implications. The oldest – and in pre-modern societies, by far the most common – form of rent/tax extraction is extraction in kind, where the farmer pays their rents and taxes with agricultural products directly. Since grain (threshed and winnowed) is a compact, relatively transportable commodity (that is, one sack of grain is as good as the next, in theory), it is ideal for these sorts of transactions, although perusing medieval manorial contacts shows a bewildering array of payments in all sorts of agricultural goods. In some cases, payment in kind might also come in the form of labor, typically called corvée labor, either on public works or even just farming on lands owned by the state.

The advantage of extraction in kind is that it is simple and the initial overhead is low. The state or large landholders can use the agricultural goods they bring in in rents and taxes to directly sustain specialists: soldiers, craftsmen, servants, and so on. Of course the problem is that this system makes the state (or the large landholder) responsible for moving, storing and cataloging all of those agricultural goods. We get some sense of how much of a burden this can be from the prominence of what seem to be records of these sorts of transactions in the surviving writing from the Bronze Age Near East (although I should note that many archaeologists working on the ancient Near Eastern economy are pushing for a somewhat larger, if not very large, space for market interactions outside of the “temple economy” model which has dominated the field for quite some time). This creates a “catch” we’ll get back to: taxation in kind is easy to set up and easier to maintain when infrastructure and administration is poor, but in the long term it involves heavier administrative burdens and makes it harder to move tax revenues over long distances.

Taxation in coin offers potentially greater efficiency, but requires more particular conditions to set up and maintain. First, of course, you have to have coinage. That is not a given! Much of the social interactions and mechanics of farming I’ve presented here stayed fairly constant (but consult your local primary sources for variations!) from the beginnings of written historical records (c. 3,400 BC in Mesopotamia; varies place to place) down to at least the second agricultural revolution (c. 1700 AD in Europe; later elsewhere) if not the industrial revolution (c. 1800 AD). But money (here meaning coinage) only appears in Anatolia in the seventh century BC (and probably independently invented in China in the fourth century BC). Prior to that, we see that big transactions, like long-distance trade in luxuries, might be done with standard weights of bullion, but that was hardly practical for a farmer to be paying their taxes in.

Coinage actually takes even longer to really influence these systems. The first place coinage gets used is where bullion was used – as exchange for big long-distance trade transactions. Indeed, coinage seemed to have started essentially as pre-measured bullion – “here is a hunk of silver, stamped by the king to affirm that it is exactly one shekel of weight”. Which is why, by the by, so many “money words” (pounds, talents, shekels, drachmae, etc.) are actually units of weight. But if you want to collect taxes in money, you need the small farmers to have money. Which means you need markets for them to sell their grain for money and then those merchants need to be able to sell that grain themselves for money, which means you need urban bread-eaters who are buying bread with money, which means those urban workers need to be paid in money. And you can only get any of these people to use money if they can exchange that money for things they want, which creates a nasty first-mover problem.

We refer to that entire process as monetization – when I talk about economies being “monetized” or “incompletely monetized” that’s what I mean: how completely has the use of money penetrated through this society. It isn’t a one-way street, either. Early and High Imperial Rome seem to have been more completely monetized than the Late Roman Western Empire or the early Middle Ages (though monetization increases rapidly in the later Middle Ages).

Extraction, paradoxically, can solve the first mover problem in monetization, by making the state the first mover. If the state insists on raising taxes in money, it forces the farmers to sell their grain for money to pay the tax-man; the state can then take that money and use it to pay soldiers (almost always the largest budget-item in an ancient or medieval state budget), who then use the money to buy the grain the farmers sold to the merchants, creating that self-sustaining feedback loop which steadily monetizes the society. For instance, Alexander the Great’s armies – who expected to be paid in coin – seem to have played a major role in monetizing many of the areas they marched through (along with breaking things and killing people; the image of Alexander the Great’s conquests in popular imagination tend to be a lot more sanitized).

Bret Devereaux, “Collections: Bread, How Did They Make It? Part IV: Markets, Merchants and the Tax Man”, A Collection of Unmitigated Pedantry, 2020-08-21.