Scientists reclaim the long lost economic history of Rome

May 17, 2018 11:40 PM

Ancient Rome’s Collapse Is Written Into Arctic Ice. "Scientists can finally track the civilization’s economic booms and recessions—thanks to the exhaust of its massive coin-making operation, preserved for centuries in Greenland’s ice sheet."
posted by homunculus (24 comments total)

I love when social science and science science work together!
posted by The Underpants Monster at 2:03 AM on May 18, 2018 [2 favorites]

Using evidence of lead and other pollutants in various soils is nothing new, though the evidence for ice may be. I went to a lecture 20 years ago tracking Roman economic expansion via pollutants; Keith Hopkins published in this as did others.

I’m delighted by this news but it’s not quite the new approach that the headline suggests.
posted by lesbiassparrow at 2:06 AM on May 18, 2018 [6 favorites]

Does this mean that the climate change denial crowd will now deny human impact on climate in the times of ancient Rome as well? Like, the lead wafted to Greenland accidentally from the.. Great lead heap fires in Siberia?
Will they see the insidious evidence of how humans affect global environment and extrapolate this to the present?
posted by Laotic at 2:22 AM on May 18, 2018 [5 favorites]

lesbiassparrow, the article mentions a study from the 1990's that reached opposite conclusions from this one. The thing that makes this study noteworthy is the sheer number of data points it uses (25000 versus 18 from the other study) and their increased ability to correlate spots in the ice with actual historical dates. It seems the technique is really taking off.
posted by Kevin Street at 2:51 AM on May 18, 2018 [13 favorites]

I love this.
posted by lokta at 4:55 AM on May 18, 2018

human impact on climate in the times of ancient Rome

I have heard that they did a lot of damage by deforestation, causing soil erosion.
posted by thelonius at 5:04 AM on May 18, 2018 [2 favorites]

thanks to the exhaust of its massive coin-making operation

torquem obstructionum? codex torque?
posted by q*ben at 6:35 AM on May 18, 2018

reached opposite conclusions from this one

Isn't "opposite" kind of a strong claim? I'd say "lower fidelity".

Take a look at Figure 2 in the new study. The previous 18 measurements appear to nearly all lie within the ranges you'd expect from the current measurements. And the current measurements have such a wildly oscillating high frequency component that you would expect to see outliers.

Even qualitatively: The previous study saw a slow rise in production during the Roman Republic, a peak around the transition from Republic to Empire, and a slow fall in production during the Empire. This study appears to turn that single peak into a twin peak with an interruption in between. If the previous study had been used to claim that there was no 1st century BC Crisis then I'd say that's now been definitively contradicted - and actually, I haven't seen that done but I wouldn't swear it hasn't happened, since using a line graph for such sparse data really does oversell it - but the general timing of the rise and fall doesn't seem too far off.

Still, now I'm suspicious of the other quantitative data source I've seen from that time period, Mediterranean shipwrecks. This one *does* show a bimodal graph, but without nearly as big a plunge in the middle, and the resolution is much much finer than the first GRIP ice cores so it's hard to blame sparse data. So what was going on? Wars interrrupted lead production but didn't have nearly the same impact on shipping? An increase in military shipping somehow offset a decrease in merchant shipping? Measuring ship wrecks gives you an oversmoothed and biased estimate of ship production?
posted by roystgnr at 7:34 AM on May 18, 2018 [8 favorites]

the general timing of the rise and fall doesn't seem too far off

Actually, let me be more specific, since I'm pretty ignorant here and I'd really like to know if my takeaway from the earlier study really has been contradicted. At first glance I don't think it has; I think both contradict the same more naive view:

If you look at the territorial expansion of the Roman Empire, it doesn't peak until around 117AD, and it wins nearly as much as it loses afterwards, so that it still has about 90% of that area for centuries until it gets divided.

The Roman Republic, by comparison, is a little pissant country, right up until the Crisis: in 146BC it's six times smaller than the empire it will eventually create; only after that does it finally start to become powerful, more than doubling in size over the next century.

But if you look at the ice cores this measurement of power looks entirely wrong! The actual economic production in the Empire is a mirror image of the Republic: no larger, and shrinking instead of growing! See Figure 3. I wish that plot was filtered with a wider window than 11 years, but it does look smooth enough to eyeball that peak production around 25AD isn't much better than around 125BC and that sustained production from 50-150AD isn't much better than from 350-150BC. In this view the territorial gains of Rome aren't actually building any power, they're just spending power! You can see a "hollowness" to the Empire in economic proxy data that is relatively invisible just looking at conquests. If anything the new study seems to make this conclusion stronger - the territorial conquests of the Late Republic aren't just uncorrelated with underlying growth, they're anti-correlated, Pyrrhic victories that dwarf the earlier eponymous example!
posted by roystgnr at 8:04 AM on May 18, 2018 [9 favorites]

This is very cool, thanks for posting!
posted by carter at 8:23 AM on May 18, 2018

Needs a plumbum tag btw ;)
posted by carter at 8:59 AM on May 18, 2018 [6 favorites]

Man, this piece is really cool work, it's just really hard to appreciate from the linked material: the graph's window makes it very very difficult to read. Worse, despite the Atlantic author's zeal for Wikipedia links to very basic aspects of Roman history like the Second Punic War, they've totally neglected to link to the actual paper in question. I had to find it eventually via reverse google image search.

author at the Atlantic needs to make more metafilter posts

Gimme a sec, I'm putting together a better figure from the data in the PNAS publication for Fig 3, because I want a better look at it.
posted by sciatrix at 9:09 AM on May 18, 2018 [6 favorites]

In the republic anyone could mint coins and in the throes of the Late Republic minting coins was about fighting it out with other aristocrats and spreading your name and that of your family in the easiest way possible: coins. So economics alone don’t give the full story. It is also worthwhile to reflect on the wealth of various conquests: Carthage and Egypt yielded huge wealth, as did Corinth. And Carthage and Greek conquests were using coinage and produced quantities of gold and silver and bronze in quantities that somewhere like Numidia or Britain wouldn’t. 146 BCE alone poured wealth in huge amounts into Rome thanks thanks to the complete destruction of Carthage and Corinth
posted by lesbiassparrow at 10:03 AM on May 18, 2018 [5 favorites]

We can similarly see the effects of Spanish colonialism through their silver smelting in South America by looking at ice cores from the ice caps of the Andes.

You can look even further back and get hints to the rise and fall of civilizations in South America for over 2000 years.

It is fascinating that usually looking back thousands or even hundres of years gives a very vague picture. But the ice caps gives us data that tells us to the year when events happened.
posted by eye of newt at 10:22 AM on May 18, 2018 [11 favorites]

YES I was just looking for that very same article which I first saw a few years ago one night at 3am when I was mad about colonialism again.
posted by poffin boffin at 10:27 AM on May 18, 2018 [2 favorites]

Have a better and slightly more manipulable figure. Note that I couldn't easily get good years on the Spanish mining bit, so I estimated by eyeballing the existing figure.

Interesting takeaway: the decline in smelting only seems to occur once the Republican Crisis is well and truly set in--economic instability seems to happen after political instability is already quite established.
posted by sciatrix at 10:31 AM on May 18, 2018 [5 favorites]

Few other thoughts--First Punic happens over the course of correlated to a sharp increase in lead emissions, but Second Punic correlates with a sharp decline-followed by a sharp increase that starts in approximately 210 BCE. It's important to note that Second Punic was a twenty-year war, and that 210 BCE actually marks the mid-point of that war--and indeed, it also marks the point at which Roman military strategy started decisively winning that war. The stimulus from Second Punic lasts all the way till 170 BCE, plus or minus a sharp dip around 190 BCE. From the helpful historical cheat sheat in the supplementals, it looks like those years are correlated with Rome heavily digging into the early years of the Hispanian conquest (ran from 194 BCE to 179 BCE) and then you get a nice bump again from all that Spanish silver until Rome starts digging heavily into modern Portugal and, if I remember right, more north-eastern territories in Spain and starts saber-rattling with Carthage leading into Third Punic.

To me, the dips during the Republic look much more like losses related to setting out heavily ambitious military conquests on foreign soil than they look like consequences of political instability. Of course, this isn't my field, and I'd need to dig very heavily into specifically mining activity as well as who owned those mines and how those controls interacted with the need to mint coins to be able to say anything that you shouldn't take with several grains of salt.

But I'm happier having gotten a better look at at least their lead emissions data, anyway. (I didn't bother digging into the other of the two datasets because it's been nearly two hours and I'm procrastinating on my own paper, but someone else is welcome to.)

muttering: why on earth dive for this level of beautiful data resolution if you're not gonna use it in the context of year-to-year history?
posted by sciatrix at 10:50 AM on May 18, 2018 [5 favorites]

This is deliciously close to the Bitcoin post.
posted by tapesonthefloor at 11:37 AM on May 18, 2018 [1 favorite]

Of course, this isn't my field, and I'd need to dig very heavily into specifically mining activity as well as who owned those mines and how those controls interacted with the need to mint coins to be able to say anything that you shouldn't take with several grains of salt.

Finding out who owned mines would be tough, I think (though I'm no expert in that area) - as far as I know they were usually own by corporations, because like tax-farming in the Republic it was too expensive for individuals to undertake. Antony did own part shares in one, but we only know that because of a jab by Cicero in the Philippics. Not sure about the empire after Augustus so much, though.

To me, the dips during the Republic look much more like losses related to setting out heavily ambitious military conquests on foreign soil than they look like consequences of political instability.

I am not sure you can disassociate those two elements: wars were part of aristocratic competition and people went for wars because they wanted the reputation of being a general. And someone once (can't remember who at the moment) went through the various careers of people who lost battles and wars spectacularly and it doesn't seem to have made that difference in later careers exactly how you did. Getting your name out there and getting elected to the position where you could lead an army were the important things, not necessarily your military reputation.

(I work on Cicero, so the various balls ups of aristocrats in the Late Republic is one of my deep and abiding interests.)
posted by lesbiassparrow at 1:26 PM on May 18, 2018 [5 favorites]

And if you're tracking economic activity and minting in the empire, the army was paid in coin and the whole payment was a giant ritual cementing the emperor's relation to the troops, so it was incredibly symbolically important. So the larger the army the more coining you'd have to do. So any period in which you have an expansion or contraction of the army will have an effect in pollutants from minting, that may or may not be connected to other economic activities. The Severans were really keen on passing money to the empire, but I think the consensus is that the economy was not doing that well in general, partially because they were throwing more and more resources there rather than elsewhere.
posted by lesbiassparrow at 2:36 PM on May 18, 2018 [3 favorites]

Does this mean that the climate change denial crowd will now deny human impact on climate in the times of ancient Rome as well?

The article doesn't really address that, but if you're interested in that, you should check out this. How anthropogenic the changes were, well, not my field.

As to the coin thing, the variable to keep in mind are the amount of lead different emperors cut the silver sesterces with. Nero wasn't that bad, and the subsequent Flavians (AD69-96) were, with one brief stumble, serious hard money emperors (that upturn on the left side of the chart is Domitian). It was later emperors who brought silver content down to 5%. Not as bad as US coins, but not great, either.

Silver weight we can track. The other variable, how many coins in toto were coins in a given year, that one's a little harder. If someone has done it, I'd be interested to know.

the army was paid in coin and the whole payment was a giant ritual cementing the emperor's relation to the troops, so it was incredibly symbolically important

Too right! Plus which, they could make or break you. It wasn't by accident that in the later empire soldiers (barbarian mercenaries, frequently) in particular noticed the cheap coins, and insisted on, and got, payment in gold. Good for them,
posted by BWA at 2:54 PM on May 18, 2018 [4 favorites]

Interesting post, thanks homunculus!
posted by Quietgal at 6:49 PM on May 18, 2018

Sciatrix, we all benefit from the positive externalities that flow from your procrastination :)
posted by mabelstreet at 2:31 PM on May 19, 2018 [5 favorites]

Construction Workers Find Rare Intact Roman Tomb: ‘The Tomb of the Athlete’ includes four bodies, a coin, offerings of chicken, rabbit and lamb and strigils, the symbol of Roman sportsmen
posted by homunculus at 5:10 PM on June 16, 2018 [3 favorites]