Broadsheet

This is the first half of the final part (I, IIa, IIb, III, IVa, IVb, Va) of our apparently five-part series laying out some general guidelines for how pre-modern armies are organized, in particular exploring the principle that armies cannot help but recreate their civilian social structures on the battlefield. Last time we looked at the importance of generating cohesion in these armies and the ways cohesion could come either organically from the underlying society or be manufactured as part of training (or not be produced at all, resulting in less effective armies).

To close out this week, I wanted to provide some examples – each relatively brief – pulling the factors we’ve discussed (recruitment principles, mobilization methods, dealing with costs, leadership and cohesion sources) into coherent military systems that emerge organically from their underlying civilian society. And since this series was always intended as ‘one for the world-builders,’ I figured the best way to do this would be to take some fictional militaries, examine them along the lines above and see what (if anything) is necessary to fix them so that the underlying civilian society and the military it generates ‘matches.’

In a lot of cases, these are going to be fictional militaries we’ve looked at before, so a lot of this will be overlapping with more detailed treatments (which I’ll link) but also we’ll get some new stuff.

In the end, I had enough examples I wanted to work through that I opted to split this last part in two. So in this part we’re going to be taking apart some examples of matching up (or struggling to do so) army and society in literature (namely my perennials, A Song of Ice and Fire and The Lord of the Rings). Then in the second half, we’ll break some new ground and look at some examples out of video games that deviate from some of the classic ‘medieval fantasy’ patterns: the standing legions of the Empire of Cyrodiil, the oddly (but interestingly) bifurcated urban defense force of Baldur’s Gate and finally some private enterprise war in the Deadfire Archipelago.

I want to be clear, the goal here is not to praise or tear down any of these examples, but to explore them, to practice thinking about how the fiction armies and societies do and don’t match. I’ve tried to avoid here picking any example that is actively really bad (thus a preference for A Song of Ice and Fire (the books), for instance, over Game of Thrones (the show)).

But first, as always, recruiting and maintaining large pre-modern armies is expensive! Much like many of those pre-modern armies, this project is supported by devolving the costs of my ruinous book-buying habit on to ~~recruits~~ readers. You can help by spreading the word to new readers and by supporting this project over at Patreon. If you want updates whenever a new post appears or want to hear my more bite-sized musings on history, security affairs and current events, you can follow me on Bluesky (@bretdevereaux.bsky.social). I am also active on Threads (bretdevereaux) and maintain a de minimis presence on Twitter (@bretdevereaux).

Westeros and Fragmented Vassalage-Based Polities

So my critiques of some of the ‘realistic’ worldbuilding of A Song of Ice and Fire and Game of Thrones (and spinoffs) are not new. To be clear, I don’t think there is anything wrong with enjoying these stories; rather my critiques emerged in a period – now largely passed, thankfully – where it was common to claim that George R.R. Martin’s work represented a truer or more faithful vision of medieval vassalage-based polities. But that era is largely passed and my sense is that the ASoIaF/GoT community largely now understands that Westeros is not necessarily the gold-standard for ‘realistic’ medieval fantasy societies. So I don’t bring this up first to bash GRRM, but rather because (unlike Middle Earth, as we’ll see) it represents close to a ‘pure’ example (notionally) of a fragmented, vassalage-based polity.

The Lannister army from the show in the field. If the books are a little off the mark, this depiction is **wildly** off the mark: this army, with neat regular blocks of men in uniform equipment marching in neat order with a heavy emphasis on heavy infantry over cavalry or light infantry, **this is the army of a wealthy, well-administered, urban state**: all things we are **explicitly** told Westeros in general and the Lannister westerlands in particular are not (remember: in the show, at least, Lannister gold ran out some time ago).

So first we should begin with the underlying society. Westeros as we see it is a complex agrarian society – that is there is quite a lot of specialization, but this is a distinctly pre-modern society in which the vast majority of the population is still engaged in agriculture or pastoralism. Now I find that Martin’s depiction of the ‘smallfolk’ – ably summed up by the Wiki – is a bit frustrating as it is mostly a collection of aristocratic stereotypes about peasants, but nevertheless this is clearly a society where the bulk of the population is a largely demilitarized peasantry. In short, it is supposed to resemble high or late medieval Europe. Above the smallfolk is a hereditary landed aristocracy which fashions itself a ‘knightly’ (mounted military) warrior aristocracy, structured through vassalage. The social distance between these two groups is yawning: Westerosi aristocrats have more in common with other aristocrats half a continent away than they do with the peasants out of their front door.¹ That social distance is not a worldbuilding problem, mind you; we see that kind of ‘trans-national’ elite (keeping in mind these aren’t nation-states so we’re using the word ‘national’ rather loosely) in a number of pre-modern societies. A French nobleman often did have more culturally in common with an English nobleman than he did with his own peasants and indeed in some cases a mounted Christian European military aristocrat might find he had more in common with a mounted Muslim military aristocrat from the Middle East than either had with their own peasants too.

So far, so good. But – as I’ve noted a few times before – when we see the armies of these polities, both in the books and in the show, they do not derive organically from this society at all. Westeros produces very large, surprisingly uniform armies which are not obviously organized into the retinues of smaller lords but rather function as large field armies tied explicitly to the largest vassals of the crown. Moreover, very large proportions of these armies are infantry (especially in the show, where the Lannister, Tyrell and Stark armies are almost entirely infantry!), composed of massed peasant soldiers. They’re also broadly uniformly equipped, often with recognizable liveries.

Likewise from the show, the Tyrell house guard. This (except for the very silly helmets) is a bit easier to talk around because the unit we see is so small, one might explain it as a small standing unit of retainers or mercenaries (but then why use that instead of the large numbers of military aristocrats one spends so much time retaining?). But I think we’re meant to take this too as indicative of what House Tyrell’s army looks like – neatly identical soldiers in identical equipment (and **heavy** armor). Again, at scale this is a kind of army House Tyrell is structurally incapable of producing: it doesn’t have the administration or revenues to build or buy it and it doesn’t have a large wealthy yeoman freeholder class to devolve the cost onto Roman-Republic-style.

In short, these resemble the armies we would expect of large, extensively administered state-based societies.

But, and I have to stress this extremely strongly, Westeros does not have a state. It was not a state under the Targaryens (they make no effort to consolidate control of the various House armies) and it sure as heck isn’t a state under the Baratheons who are even weaker in terms of central power.

So what ought we see? Well, let’s return to that underlying society.

The core of these armies are going to be that mounted military aristocracy. It’s possible in some regions (the north, perhaps?) the aristocrats might also fight on foot, but we’re still looking at the aristocracy. Now the core landed aristocracy is going to be really small, but what is going to expand out this class are two kinds of soldier that GRRM has largely neglected: unlanded knights bachelor and non-aristocratic ‘men at arms’ (men who fight like knights but do not have the social status of knights). GRRM has some unlanded knights, but not many – but in this sort of society, such men are going to be ubiquitous in the households of those landed elites.

After all, most of the wealth in this society is held by a landed military aristocracy (the lords) who want to develop private military force and lack a state, so they’re going to do so in their household, by retaining (as retainers) full time warriors. And in this society, we see very clearly that full time warriors are almost invariably mounted heavy cavalrymen. So while the number of lords and their families is small, they can retain a bunch of non-noble heavy cavalrymen as part of the retinues, though we’re still dealing with armies that are likely much smaller than the massive armies Martin reports: whereas Martin has armies reaching the upper tens of thousands, we might instead expect the armies of the most powerful houses to at best be fielding a few thousand to perhaps 10,000 or so mounted men at arms.

The new House of the Dragon series **keeps doing this**: here is the Hightower Army and again it is a long line of uniformly equipped heavy infantry, a kind of army this society is incapable of producing. While the books are not always better than the show, when it comes to understanding what kinds of armies can exist in this world…the books are generally better than the show.

In short, to use our typology, our first component here is a retainer-based army composed of a warrior class, recruited on a vocational principle, with military costs largely devolved (these guys or their lords purchase their horses and armor as a private expense). Cohesion is provided through a mix of warrior-class cohesion, probably combined with collective training in small cavalry units within those noble households. We probably ought to expect these men to perform quite well on the battlefield, given how strong that cohesive bond is likely to be.

Now, below this, every army needs infantry, especially because – as noted above – the cavalry components of these armies are still small. But those major Houses didn’t just become states when it was time to equip their infantry, so the infantry – drawn from the commons – is going to be recruited also using non-state structures. That means that equipment and wage costs also have to be substantially devolved, because none of these polities has the administrative infrastructure to handle the complexity of these costs (note that this is as much or more a question of complexity as about raw revenues!).

That leaves the warlords of Westeros essentially two options and we might expect them to use both: they can raise their own peasants or they can hire mercenaries.

If they raise their own peasants, this is going to be clientage principle recruitment, because the administration isn’t there for an employment-based system and the smallfolk don’t have any political entitlements to tie to military service anyway (notably Westeros lacks enfranchised little urban republics to provide urban militias). We should thus expect costs to be devolved, probably using a brigaded household model simply because the smallfolk seem too poor to expect individual households to furnish a man with his equipment. Nevertheless, the equipment that results from this is going to be both poor and non-standard (it would be hard to tell a Tyrell peasant-soldier from a Lannister peasant-soldier if you saw one on the road). And the cohesion principle is pretty obviously weak: these guys don’t have a strong corporate identity and their masters cannot afford to keep them under arms long enough to drill them. They’ll get to the battlefield, but often perform poorly. And because we have to brigade a bunch of households to get a soldier, we should still expect the numbers here to be smaller: low tens of thousands, not mid- or high- tens of thousands.

Ok, credit where due: **I actually can buy that the North might produce an army that looks like this**. The North doesn’t seem to share the same martial culture as southern Westeros (though to judge by Ned Stark’s children, by *ASoIaF*, some of the mythology around that kind of warfare is filtering in) and so I can imagine that it might have a military aristocracy that fights on foot. Notably **their equipment is not uniform** because we’re still devolving equipment costs and so each fellow has acquired his own armor, though that’s enough similarity between them that we get some sense that they are all thinking about the same heavy infantry tactical system.
The real problem is how **drab** they are. These are men of importance and station! They’re wearing **expensive** equipment! They would want to look nice!

The alternative would be mercenary infantrymen, recruited en bloc (likely via contractors) using an employment principle and paid in cash. Since these houses don’t have a lot of revenue because they have very limited state capacity, their ability to engage these fellows is also going to be quite limited, but it isn’t hard to imagine how valuable they’d be, especially for providing specific military skills that aren’t ‘mounted military aristocrat,’ which obviously the peasant levies will also generally lack. If there were polities in Westeros that produced good infantry – because they had tight civic militias or other strong communal structures – we should expect them to be in heavy demand as mercenaries, just as Greek hoplites or Swiss pikemen were in their day. Good infantry, after all, is nice to have, but the Great Houses of Westeros are structurally largely incapable of producing good infantry at scale.

In short the military that flows from Westeros social organization is meaningfully different than the one Martin imagines. It is much smaller (no 100,000 man strong Tyrell armies!), more fragmented and much less ‘regular.’ Not only does the king have to care what Tywin Lannister thinks, but Twyin Lannister has to care what Lord Broom thinks and Lord Broom has to care what his retainers think and so on. Tywin’s Lannister army would likely be broken up into dozens of irregularly sized and structured retinues (of which his own would be the largest). Notably, ‘landless knights’ would be a key commodity in this system, an essential military resource that everyone with land and money is trying to attract (which in turn means those retainers have some bargaining power too), in part because none of these fellows will have a lot of faith in their poorly and irregularly equipped, weakly motivated infantry.

Crucially, this is a society defined by low state capacity (because it is, in fact a non-state society), which limits what the king and his lords can do at almost every turn.

Now to be clear, I don’t want to make it sound like Westeros – particularly the Westeros of the books – is a complete failure here. I think we could actually bring the armies of Westeros into line with their underlying society with fairly modest changes: shrink both the world size and the armies to a scale that fits a personalistic, vassalage based mobilization system and acknowledge that these polities are going to really struggle to employ good infantry at scale (lacking the revenues to recruit mercenaries or the social systems to effectively mobilize their peasantry), so they’re going to rely on their cavalry, which is in turn going to put sharp limits on the kind of warfare they wage. Finally, we’d want to flesh out the class of mounted man-at-arms and landless knight – present in Martin’s writing, but less common perhaps than they ought to be.² The resulting world would feel smaller (it would be smaller) but that makes sense: these sorts of polities and their military systems do not durably scale.

Infantry and Cavalry in Rohan

I’d argue we can see a ‘heavy cavalry culture’ done a bit better with the Lord of the Rings‘ Rohirrim, although with the caveat that Tolkien is developing something closer to an early medieval society which still retains a relatively strong (perhaps fading) infantry tradition, as opposed to Westeros’ distinctively late medieval (or really early modern) sense; these are as we’ll see fundamentally quite different societies and as a result they produce different armies (albeit I think the armies of Rohan are more tightly fitted to their society).

Once again, we should sketch out Rohan’s society first. This is also a complex agrarian society, albeit less complex than Westeros and seemingly with a fair bit more pastoralism (in the form of ranching or fairly short-range transhumance, given that this society still lives in villages, rather than nomadic pastoralism). Military power is still somewhat fragmented in this society – men like Éomer and Erkenbrand appear to have some independent access to military force (they have their own retinues)³ but this is both a smaller and ironically more centralized kingdom than Westeros, but what make sit similar in a lot of ways is that state capacity remains low.

What I mean by that is that while on the one hand Théoden’s authority over his subordinates remains notionally higher (Tywin Lannister is a more independent figure than Erkenbrand, by custom and general understanding), Théoden still lacks anything like an administrative apparatus or bureaucracy and instead has to rule through his aristocracy. What’s different and thus what makes Rohan a bit more centralized in its structure is that Théoden has more latitude to hand-pick the top level of that organization chart, the three Marshals of the Mark (he initially picks himself, his son and his nephew, with his son being replaced by Erkenbrand after Théodred was killed), rather than being stuck with a specific local mega-aristocrat (like Tywin Lannister, Mace Tyrell, etc. etc.). Those commands (which historically are what will evolve into the highest reaches of the ‘feudal’ European nobility) are not yet wholly hereditary, though the fact that command in the Westmark immediately devolves to Erkenbrand Lord of the Westfold (the largest chunk of the Westmark)⁴ may suggest that, in the absence of a suitable member of the royal house, there’s a strong expectation that overall leadership ought to fall to a major local aristocrat.

As an aside, the fact that Rohan, resembling an early medieval kingdom is more effectively centralized than Westeros, which resembles a late medieval kingdom, should serve as a useful reminder that historical processes like centralization do not proceed only in one direction. It is not always the case that later societies have more centralization or administrative capacity.

We also need to talk about the situation of common folk of the Rohirrim. We don’t see much of them, but there are some assumptions I think we can make (which largely conform to Tolkien’s own pretty obvious Anglo-Saxon inspiration for these fellows). First, the Rohirrim aristocracy strikingly present themselves as having more culturally in common with their commonfolk than with neighboring aristocrats: they have their own language (that is, the aristocracy has not abandoned Rohanese for Westron) and their own internal term for themselves (an endonym) as Eorlingas, ‘people of Eorl’ which appears to include the commonfolk. Notably, the aristocracy, while clearly large landowners, do not appear to be titled: apart from Théoden King himself no one gets hereditary titles appended to their names (the Marshals being appointed positions). They also have a muster of all able-bodied men, implying a tradition of universal military service and thus a peasantry (I’m including their shepherds here) that hasn’t been entirely demilitarized. That last point matters a lot and signals, I think, quite a different underlying social structure than the one we see in Westeros.

This arming scene is a major emotional point in Peter Jackson’s film and it makes sense that in the context of a siege, the lord’s (in this case, the unseen Erkenbrand) armory is being emptied out to equip as many men as possible, but we ought probably to have seen a lot of these fellows show up with equipment. We know that Rohirrim armies regularly include infantry (even if their strength is in cavalry) and that infantry must come from somewhere – given the limited administration, the only real option is a self-equipping yeomanry.
We might then, in a desperate moment like this, not only see the lord’s armory emptied out, but individual middling-peasant households passing around old or surplus equipment to friends and relatives (pulling old arms and armor out of temple storerooms where they had been dedicated for last-ditch defenses was a standard trope of ancient Greek and Roman warfare, for instance).

Taken together, what I think we’re looking at is a landholder aristocracy governing a society mostly of free peasants rather than serfs. In something akin to the Carolingian system, there is probably a property line which makes a landowner liable for cavalry service (which thus defined the lower bound of the aristocracy), while landowners below that level are liable for infantry service (a ‘select levy’) and landowners much above that level are expected to furnish not only themselves but a larger retinue (thus we hear of the ‘knights of the king’s house’ and Marshals of the Mark having an Éored (120 mounted men) as part of their household). We should probably also assume a substantial number of farmers or herders who are simply considered too poor to serve (possibly expected to supply men for garrison service on a brigaded household model or as part of a ‘general levy’ in a local crisis).

Now as with the example above, Peter Jackson’s adaptation is not a one-to-one reproduction of the armies of the books (as we’ll see with his use of plate armor for Gondor), but I think this shot actually captures the sense the books give of Rohan’s society really well because we have a mix of all three of our fighting social strata here. In the back, around Théoden we have some military aristocrats in quite fine armor – full time combatants who would normally be on horseback. Farther forward, we see some fellows in less resplendent but still fairly heavy scale armor, with helmets and I would guess these are our ‘select levy’ of well-to-do peasants who might have been infantry as part of a field army. And then finally, towards the center, we have some fellows who lack cuirasses or helmets, who probably represent our ‘general levy’ of all able-bodied men.

The military organization then flows that social structure. The aristocracy fight at mounted heavy cavalry and are organized into retinues around the major magnates who on the one hand derive their wealth from large landholding but on the other hand owe their official positions to the king.⁵ We meet a fair number of these magnates (Erkenbrand, Grimbold, Elfhelm, along with of course Éomer and Théodred). There is a clear preference in these appointments, when not granted to a man of the king’s family, to use someone local: Erkenbrand commands in the West-mark because he is from the West-mark. Éomer will end up making Elfhelm command in the East-mark and by all indications Elfhelm is from the East-mark as well, given that he was in Éomer’s retinue as Third Marshal of the Riddermark with that geographic area of command.

Via the still amazing LOTR Project’s Map of Middle Earth, a map of Rohan. Note that the Westfold is only a smaller subunit of the West-mark which seems to have included all of the lands west of the Entwash except those around Edoras itself (while the East-mark seems to have covered the eastern part of the kingdom).

Meanwhile, as I noted back in the Helm’s Deep series, we get a better sense of what we might term the ‘select levy’ of Rohan (the infantry force kept in the field by Erkenbrand) as well as the ‘general levy’ of all able-bodied men who have fled to Helm’s Deep. We’re pretty clearly told that the levies of Rohan are raised geographically (Erkenbrand has the Westfold’s men, who have a distinct sub-regional identity as ‘Westfolders’ and the ‘musters’ are by region); we don’t see the lower levels of command but there’s no reason to assume they’re not like the higher levels: local magnates lead the levies from their home area. That in turn explains the cohesive principle we see: when the Rohirrim get into trouble – common infantry and aristocratic cavalry alike – they invariably ‘clump up’ around the magnates, which suggest pretty close civilian ties. It makes sense: where do the regular infantrymen go when things are bad? The men of their village clump up together around their village leader (the local Big Man) who is also their unit commander and who they know fairly well. The comparative lack of social distance – implied by the common culture, language and lack of titles above – matters here for making this kind of cohesion work.

So my read on Rohan is that it is a complex, non-state agrarian/pastoralist polity, with a freeholding farmer class (a yeomanry) recruited regionally under a cultural norm of universal military service (at least for landholders), with an elite class that understands itself as a mounted military aristocracy (recruited as a warrior class, defined by wealth), where the cohesive principle is probably tight clientage ties between the infantry and their magnates and then horizontal ties between the magnates and each other. But that works because these fellows seem to actually know each other (in contrast, for instance, to the far more insulated noble class in Westeros).⁶ In terms of cost, this is clearly a system where costs are devolved, but the sense we get, given the performance of Rohan’s infantry against Saruman, has to be that the infantry class has preserved a bit more of their wealth against the aristocracy, again leading to somewhat better infantry, although it is worth noting that outside of the king’s immediate retinue, Rohan’s army is not uniform in its equipment.

Men of Gondor

Unsurprisingly, I think that Gondor – particularly book!Gondor in The Lord of the Rings is also an effective example of matching a military to its underlying society, but it is particularly interesting here because it is a composite force: different components are recruited under different principles, equipped differently, probably paid differently and so on. For large states, composite forces were very common.

And Gondor (at least under the last steward, Denethor II), is a composite polity and has a composite army to match. Gondor is also a complex, agrarian society, but a fair bit more complex than Rohan, with quite a few proper cities (Minas Tirith, of course, but also Pelargir, Dol Amroth and others) and evidently a fair bit of specialization. If the model for Rohan seems to have been Anglo-Saxon England, the model for Gondor seems to me fairly clearly to be the Eastern Roman (Byzantine) Empire, complete with a beacon system, and something like the tagmata and theme systems. Given the level of organization we see – Denethor is capable of large-scale building projects (like the repair of the Rammas Echor), substantial mobilizations (including the orderly evacuation of the Pelennor Fields) and maintaining a standing military force – I tend to conclude that Gondor is a state society, albeit that state power has frayed quite a bit around the edges (and of course part of the story is that it will be reasserted by Aragorn as king). Though we never see them, I think we ought to safely assume Denethor has some bureaucracy in addition to his military command structure, which lets him direct Gondor’s efforts from his high hall.

In particular, Gondor is split between the core territory around its capital and its subordinate regions, described as ‘fiefs’ and evidently entrusted to the control of a particular lord. Frustratingly, of these lords, the only one for which we can be sure we know how lordship is assigned is that of Belfalas, governed by the hereditary Prince of Dol Amroth (Prince Imrahil at the time of the War of the Ring), who has a different title from all of the other regional leaders but we do get references to these fellows equipping men out of their households, so I think we should understand them as local rulers who are vassals to Minas Tirith rather than appointed officials. So we have a core state with autonomous vassals making up its periphery; in this case the core state is geographically fairly small but clearly makes up the bulk of the military power: despite Minas Tirith’s long decline, it is a major population and economic center.

And lo! the military system basically follows from that political structure.

Because Gondor has a state at the core of its polity with the resources to manage massive construction projects and the like, he has a substantially wider range of options for the kind of military it will have. And it ends up having a bit of everything: a standing military centered on Minas Tirith but also a mix of other military systems drawn from its constituent regions.

First, the core of Gondor’s armies seem pretty clearly to be a standing, professional force, albeit perhaps not a very large one. The two components we see very clearly are the Guards of the Citadel and the Rangers of Ithilien. The Guards of the Citadel are pretty explicitly a professional force: Beregond is explicit that he is not any kind of aristocrat, but is still a full-time soldier in the Third Company of the Citadel (RotK 42). Given the fact that they are left effectively permanently deployed, it seems like the Rangers of Ithilien are similarly a professional force. To reach a little father, in Unfinished Tales (260 fn. 17) we get a title, “ohtar” for a “fully trained and experienced” footsoldier who was not, however, a knight, which also suggests to me (alongside Beregond’s use of the phrase ‘man at arms’ to seemingly mean the same: a man for whom war was a profession) that Minas Tirith has a substantial body of professional infantry at the core of its armies. We’re quite explicitly told that at least the Guards of the Citadel are equipped at state expensive, for they have a unique livery, but honestly it seems likely to me that the whole of this professional force was state-equipped, which is why we’re told that the livery is unique (in design and materials), rather than being told that these men were unique by having an issued livery at all.

Doubtless in an emergency this would be supplemented by drawing up the rest of the able-bodied male populace, but we’re not given a clear sense for the city of what that would look like. I find myself wondering if under normal circumstances, since Gondor is almost always in some kind of low-intensity conflict with Mordor, if the professional core wasn’t always supplemented by rotating conscription or some kind of reserve among the men of the city.

Peter Jackson has taken some larger liberties with Gondor’s infantry. For one, he’s made them almost entirely uniform (except for the Guards of the Citadel), when we’re told in the books quite explicitly they are not. But he’s also put them in plate armor, which is effectively unknown in Middle Earth, as Tolkien resolutely sticks to an early medieval military material culture milieu where scale and mail represent the best available armor.
That said, I can believe that Gondor does have some professional, state-equipped heavy infantry – indeed, we’re told they have at least three companies of it in the Guards of the Citadels and presumably more ‘regular’ soldiers beyond those.

Then we have the forces of Gondor’s fiefs and here it is useful to just reproduce the passage in which they show up:

The men of Ringló Vale behind the son of their lord, Dervorin striding on foot: three hundreds. From the uplands of Morthond, the great Blackroot Vale, tall Duinhir with his sons, Duilin and Derufin, and five hundred bowmen. From the Anfalas, the Langstrand far away, a long line of men of many sorts, hunters and herdsmen and men of little villages, scantily equipped save for the household of Golasgil their lord. From Lamedon, a few grim hillmen without a captain. Fisher-folk of the Ethir, some hundred or more spared from the ships. Hirluin the Fair of the Green Hills from Pinnath Gelin with three hundreds of gallant green-clad men. And last a proudest, Imrahil, Prince of Dol Amroth, kinsman of the Lord, with […] a company of knights in full harness riding grey horses; and behind them seven hundreds of men at arms, tall as lords, grey-eyed, dark-haired, singing as they came. (RotK, 46)

I should note that, in a slightly earlier passage, we also get Forlong the Fat, Lord of Lossarnach, with “a dusty line of men, well-armed and bearing great battle-axes.”

What I love about this passage is that it not only applies our principle of militaries reflecting their civilian societies to Gondor itself – a composite kingdom has a composite army – but it also applies it to the component parts! One gets the sense that Belfalas (with its big city at Dol Amroth) are the most state-like of the fiefs and so they have an army that looks at lot like Minas Tirith’s army: a company (about a hundred) mounted knights, matched by seven hundred men-at-arms which – given their contrast between the other groups, I think we ought to understand as also being professionals, or at least well-trained in addition to well-equipped. By contrast, from the hill country of Morthond, we get five hundred bowmen led by what is evidently a ‘family affair’ of rule there, given that it is Duinhir with his two sons commanding them: a smaller, poorer community that fights in a way that fits with coming from a hard-scrabble kind of place.

Via the still amazing LOTR Project’s Map of Middle Earth, a map of Gondor with many of the component ‘regions ‘fiefs’ labeled.

We get some class-divisions too, particularly from Anfalas, where the great mass of men – presumably a poor peasant levy – are poorly armed saved for the household guard of their lord. Of course that strongly suggests that outside of Minas Tirith, Belfalas and perhaps Lossarnach (which seem to have fairly uniform equipment and perhaps represent the remains of the decaying Gondorian ‘state’ with professional troops and state-issued arms), these fellows are equipping themselves and that most of the costs of their service have likely been devolved either onto the men themselves or their lords (and quite evidently Golasgil has opted to spend those resources on his household guard and not on the rest of his troops; one wonders how that decision will play with the newly crowned King Elessar).

Notably, this is very clearly an infantry-focused force. That makes quite a bit of sense too, because Gondor is substantially more urban than Rohan or, for that matter, Westeros.⁷ The more urban societies get, the more infantry-focused they tend to be, for the obvious reason that raising horses requires a lot of space. Even though it is clear that Gondor’s population has declined, its military tradition still remains infantry focused (with cavalry support) and that too is a product of its economic and cultural structures (urban and state-based).

And again, because the infantry matter, this society can develop cohesion in them: for the professional core, that is probably a professional cohesion. One imagines the Guards of the Citadel are quite stubborn on the battlefield given that we see how intense their professional ethos of obedience to orders goes. On the other-hand, for many of the men of the fiefs, they arrive at Minas Tirith in fairly small, relatively tight groups, organized around leaders that are quite evidently familiar to them. One imagines that the bowmen of Morthond, for instance, probably all know each other and are tightly connected by bonds of clientage to their lord and his sons (notice that he doesn’t have a household guard – this militia is his army).

So we have a range of components, each with its own likely methods of recruitment and supply. We have a core of professionals, equipped by the state, housed and presumably trained together, with an appropriately professional cohesive principle, supported by levies recruited locally, with their costs devolved onto local lords and relying on organic cohesion arising out of their common communal bonds.

The result is something of a messy composite army rather than a ‘cookie-cutter’ army that is unrealistically uniform. And that’s probably more or less right: even the Romans, close to the gold-standard for pre-modern military organization west of the Ganges were never perfectly uniform and always made use of the forces of allies, client kings and subject peoples, creating composite forces.

Next time, we’ll keep this going by turning to look at some societies and armies from video games that, as noted, deviate a bit more from the ‘standard’ medieval fantasy pattern and think a bit about standing professional armies, urban militias and military contractors in substantially more complex state societies.

The summer experiment fest is on:)

Session 6: Experimental Economics | Department of Economics

Thu, Aug 6 2026, 9:00am - Fri, Aug 7 2026, 7:00pm PDT
Gunn Building, 366 Galvez Street, Stanford,

Thursday, August 6, 2026

Aug 6

9:00 am - 9:30 am PDT

Check-in and Breakfast

Aug 6

9:30 am - 9:45 am PDT

Introduction

Aug 6

9:45 am - 10:45 am PDT

Session 1 (Chair: Muriel)

Aug 6

9:45 am - 10:15 am PDT

AI Sycophancy and Decisions

Presented by: John J. Conlon (Carnegie Mellon University)

Peter Schwardmann (Carnegie Mellon University)

We examine whether sycophantic AI advice distorts decisions. Our experiment involves 1,500 participants in 30 decision environments that span core domains in economics and the social sciences. We find that interacting with an AI that is broadly representative of consumer-facing models depolarizes choices on average, moving participants away from their initial leanings. This result appears despite the LLM being measurably sycophantic: it disproportionately supports users’ initial leanings and uses agreeable, flattering language. Depolarization occurs across moral and non-moral, objective and subjective, strategic and non-strategic, and complex and simple tasks, and despite the vast majority of researchers in an expert survey expecting polarization. Next, we show that sycophancy is behaviorally relevant—a treatment increasing AI sycophancy reduces depolarization—but that it is outweighed by the apparent informativeness of LLM advice. Finally, we ask whether market forces are likely to push toward greater polarizing effects outside our experiment or in the future. On the supply side, we show that our baseline LLM’s level of sycophancy is typical of leading models and that these models are not becoming substantially more sycophantic over time. On the demand side, we show that participants do not prefer greater sycophancy, do not select into AI advice in tasks where it is more polarizing for them, and exhibit greater depolarizing effects when they are more frequent AI users outside of the experiment.

Aug 6

10:15 am - 10:45 am PDT

Preference for Explainable AI

Presented by: Alex Chan (Harvard University)

Participants acted as loan officers deciding whether to approve real $10, 000-loans issued by a private U.S. lender using an AI’s default-risk predictions. When explanations revealed that the AI penalized non-White or female borrowers, participants were more likely to override the AI’s profit-maximizing recommendation. When their bonuses depended on repayment, however, they sought predictions but avoided explanations, consistent with willful ignorance; this effect faded when explanations were framed as purely financial or demographics were hidden. A secondary experiment reveals a novel bias: participants failed to reason contingently and undervalued explanations even when these complemented private information and improved decision accuracy.

Aug 6

10:45 am - 11:15 am PDT

Coffee Break

Aug 6

11:15 am - 12:30 pm PDT

Session 2 (Chair: Lise)

Aug 6

11:15 am - 11:45 am PDT

Narratives, Belief Movements, and Economic Fluctuations

Presented by: Tony Q. Fan (Lehigh University)

Tilman Fries (Ludwig Maximilian University of Munich)

We study how the construction and transmission of narratives—interpretations that explain observed data—systematically distort belief formation. In a dynamic environment where signals are generated by a potentially evolving state, we show that popular, well-fitting narratives tend to overfit the data and thereby push beliefs toward greater extremeness and volatility. We test this prediction in a controlled experiment that directly compares beliefs formed with and without exposure to a singular, endogenously constructed narrative. Participants exposed to such narratives form substantially more extreme beliefs, overreact to recent data, and exhibit more volatile belief movements over time. These results identify a mechanism through which narrative-based reasoning induces overreaction to news—one that likely matters broadly given the central role of narratives in economic communication.

Aug 6

11:45 am - 12:15 pm PDT

People as Intuitive Modelers: How Model Complexity Adapts to Data

Presented by: Sevgi Yuksel (New York University)

Guillaume Frechette (New York University) and Emanuel Vespa (University of California, San Diego)

We study whether and how people respond to a fundamental tension in model selection: simple models generate high bias and low variance, whereas complex models generate low bias and high variance. We report results from an experiment in which participants rely on a limited sample of observations to construct mental models describing the relationship between two variables and are rewarded based on the out-of-sample predictive accuracy of these models. In aggregate, behavior is broadly consistent with people acting as intuitive modelers who respond to the simplicity–complexity tradeoff. Model complexity varies systematically with the size and nonlinearity of the sample, but willingness to improve in-sample fit declines when doing so requires more complex models. The main deviation from optimal benchmarks is in the direction of underinference, driven by both a preference for overly simple models and mistakes in model construction conditional on the chosen complexity level.

Aug 6

12:15 pm - 12:30 pm PDT

Communicating with Data Generating Processes: An Experimental Analysis

Presented by: Agata Farina (University of Chicago)

Clément Herman (Princeton University)

In many applications, agents can more easily influence how data are generated than manipulate the data themselves. For example, students choose which classes to take but cannot modify their grades once assigned, and firms determine how performance indicators are calculated rather than directly altering results. This paper experimentally studies information transmission when data are generated through an unobservable, strategically chosen process. We focus on settings where an informed sender—such as a student or a firm—privately selects a data-generating process (DGP)—a portfolio of classes or an accounting methodology—to shape the beliefs of an uninformed receiver, such as an employer or an investor. Across treatments, we vary which DGPs are feasible and whether some come at a cost. These variations span different levels of information verifiability and capture, within a unified framework, the core insights of disclosure, cheap-talk, and signal- ing models. Our findings reveal three main patterns. First, while senders select their DGPs strategically in line with theoretical predictions, receivers often fail to account for this strategic selection. Second, introducing differential costs across feasible DGPs mitigates this DGP selection neglect. Third, while receivers’ biases are robust across environments, their consequences vary: information transmission falters most when the evidence receivers observe is highly sensitive to the sender’s DGP choices. Finally, increasing transparency about the selected DGP—a policy often advocated in practice—does not, in general, improve information transmission.

Aug 6

12:30 pm - 2:00 pm PDT

Lunch

Aug 6

2:00 pm - 3:15 pm PDT

Session 3 (Chair: Manu)

Aug 6

2:00 pm - 2:30 pm PDT

Understanding Support for Inefficient Environmental Policy Instruments

Presented by: Dmitry Taubinsky (University of California, Berkeley)

Chenxi Jiang (Massachusetts Institute of Technology), Maximiliano Lauletta (Federal Reserve Board), Ro’ee Levy (Tel Aviv University), and Joseph S. Shapiro (University of California, Berkeley)

Many governments use environmental standards rather than more cost-effective market-based instruments like pollution taxes or cap-and-trade markets. Using a nationally representative survey experiment, we study whether and why limited understanding of economic principles helps explain this practice. Holding environmental impacts constant, respondents prefer standards over market-based instruments, and prefer producer taxes and cap-and-trade over consumer taxes. These preferences reflect consumers’ beliefs about how these policies will affect electricity bills. Respondents also prefer the weakest environmental targets for consumer taxes and the strongest targets for standards, which suggests that policymakers face a tradeoff between policy stringency and cost effectiveness. A separate survey of environmental economists shows that they have strikingly different beliefs about the effects of environmental policies than the respondents in our representative survey. For example, typical respondents—in contrast to environmental economists and textbook economic theory—believe that environmental standards increase consumer energy bills less than market-based instruments do. Educational videos on pass-through and cost-effectiveness of policies affect policy support and close some of the gap between nationally representative respondents and experts, which suggests that economic literacy is a factor in voters’ preferences.

Aug 6

2:30 pm - 2:45 pm PDT

What Motivates Partisan Selective Exposure? Experimental Evidence from the 2024 US Presidential Election

Presented by: Peter Robertson (Stanford University)

Matthew Gentzkow (Stanford University), Michael Thaler (University College London)

Partisan selective exposure — the tendency of partisans to consume like-minded news — has been widely documented in the United States, but its drivers remain debated. This paper studies the relative roles of two commonly proposed motives for polarized news choice: (i) disagreement about the accuracy value of different news sources, and (ii) disagreement about sources’ non-accuracy value, such as identity affirmation or belief confirmation. To disentangle these motives, we run large-scale experiments over 3,785 participants with both real and artificial news sources in which participants choose a source to help them predict the winner of a swing state in the 2024 US presidential election. We employ two separate experimental manipulations which affect how people are predicted to trade off accuracy and non-accuracy value in canonical models of selective exposure. Despite documenting substantial selective exposure in our experimental environment at baseline, we find precise nulls across contexts on both manipulations: neither increasing the relative value for accuracy nor non-accuracy motives affects the degree to which participants choose co-partisan sources. Meanwhile, participants are highly sensitive to source accuracy: exogenously increasing the perceived accuracy of an artificial source leads to a sizeable increase in the share of participants who choose it. Our results, both interpreted in reduced form and through the lens of a discrete choice model, indicate that partisan differences in perceived accuracy are largely sufficient to explain the level of selective exposure we observe, and that non-accuracy motives play a limited role.

Aug 6

2:45 pm - 3:15 pm PDT

Incentives, Information, and Reminders for Bureaucrats: Overcoming Barriers to the Scale Up of an Effective Policy

Presented by: Gautam Rao (University of California, Berkeley)

Patrick Agte (Stockholm School of Economics), Daniel Morales (Tecnologico de Monterrey), Christopher Neilson (Yale University), and Sebastián Otero (Columbia University)

Scaling up effective policies often requires the attention of frontline bureaucrats with many competing responsibilities. Even when policymakers adopt effective programs, implementation may not follow. In a nationwide experiment in the Dominican Republic, we test interventions to increase school principals’ implementation of an educational program proven effective in a previous RCT. Only 37% of control schools verifiably implemented the intervention when ordered to by the Ministry of Education, compared with 86% in the original trials. Implementation was no higher among schools that previously participated in the RCT, suggesting that learning costs do not explain non-adoption. We find precise null effects of sharing research evidence, providing modest financial incentives, or offering implementation assistance. In contrast, additional reminder calls increased implementation by 20 percentage points. A second experiment targeting a different mandated program yields the same pattern: reminders produce large effects, while monitoring messages have smaller effects. Our findings point to limited attention among bureaucrats as a central barrier to scaling policies.

Aug 6

3:15 pm - 3:45 pm PDT

Coffee Break

Aug 6

3:45 pm - 4:45 pm PDT

Session 4 (Chair: Christine)

Aug 6

3:45 pm - 4:15 pm PDT

Cognitive Guidance in Matching Problems

Presented by: Muriel Niederle (Stanford University)

Lucas Coffman (Boston College), Yao Luo (Boston College), and Emanuel Vespa (University of California, San Diego)

Aug 6

4:15 pm - 4:45 pm PDT

Style Over Substance: The Oversized Role of Presentation Details in School-Choice Matching Systems

Presented by: Alex Rees-Jones (University of Pennsylvania)

Lucas Coffman (Boston College), Tayfun Sönmez (Boston College), Zamir Ticknor (University of Pennsylvania), and Alexander Whitefield (University of Pennsylvania)

Aug 6

5:30 pm - 5:30 pm PDT

Drinks and Dinner at Muriel's house

Friday, August 7, 2026

Aug 7

9:00 am - 9:30 am PDT

Check-in and Breakfast

Aug 7

9:30 am - 10:45 am PDT

Session 1 (Chair: Christine)

Aug 7

9:30 am - 10:00 am PDT

When Are Decisions Improvable: An Evaluation of Diagnostic Methods

Presented by: Charles Sprenger (California Institute of Technology)

B. Douglas Bernheim (Stanford University), Aldo Lucia (Ohio State University), and Kirby Nielsen (California Institute of Technology)

We evaluate three methods for identifying improvable choices: documenting specific misconceptions (the Characterization Assessment method), gauging confidence in choices (the Decision Confidence method), and showing that specific behavioral patterns in the domain of interest also emerge in a related domain where they are objectively suboptimal (the Pattern Matching method). In experiments involving risky choice, the three methods imply that different choices are improvable and have conflicting implications regarding legitimate risk preferences. We clarify the assumptions underlying each method and reevaluate the evidence on risk-taking in light of their limitations.

Aug 7

10:00 am - 10:30 am PDT

Valuations Under Tradeoff Complexity

Presented by: Jeffrey Yang (University of California, Santa Barbara)

Cassidy Shubatt (Harvard University)

Valuation tasks are a workhorse method for testing theories of individual preferences. However, a body of evidence suggests that complexity produces systematic measurement error in valuations, which raises the question of how researchers should interpret and utilize valuation data. To formally study this issue, we develop a model of complexity-driven noise in the valuation of risky prospects, in which the difficulty of comparing options to prices produces systematic noise in their valuations. We show how this model of noise can explain a number of documented valuation patterns that are difficult to rationalize under prevailing theories of risk preferences, as well as novel experimental evidence of systematic inconsistencies across valuation formats. We then characterize which valuation-based tests of preferences are robust to complexity in our model. While complexity distorts the levels of valuations in our model, differences between valuations can be informative, so long as complexity is held fixed across valuation tasks. We provide a formal criterion for robustness and apply it to valuation designs in the literature.

Aug 7

10:30 am - 10:45 am PDT

The Structure of Sequential Updating

Presented by: Kim Sarnoff (Ohio State University)

Many real-world inference problems unfold over time: employers learn about ability across tasks, consumers evaluate products through repeated use, and policymakers revise beliefs as new data arrive. Yet despite its ubiquity, research on dynamic updating has largely focused on a single implication of Bayesian reasoning: order independence. This paper experimentally tests a broader set of restrictions implied by Bayes’ rule, emphasizing both order independence and the previously unexamined property of prior sufficiency: the principle that the most recent posterior should serve as a sufficient statistic for past information. In a multi-period updating experiment with a rich set of parameters, participants repeatedly revise beliefs after receiving signals of varying strength and structure. Three main results emerge. First, only roughly a third display order dependence, overreacting to conflicting signals. Second, violations of prior sufficiency are widespread: beliefs formed sequentially tend to grow more extreme, and models assuming prior sufficiency, such as Grether (1980), fit poorly beyond the first update. Finally, the data indicate that participants process signals in aggregate, explaining prior sufficiency violations.

Aug 7

10:45 am - 11:15 am PDT

Coffee Break

Aug 7

11:15 am - 12:30 pm PDT

Session 2 (Chair: Muriel)

Aug 7

11:15 am - 11:45 am PDT

Promise Keeping and the Internal Judge

Presented by: Chloe Tergiman (Pennsylvania State University)

Sorravich Kingsuwankul (Vrije Universiteit Amsterdam) and Marie Claire Villeval (Université Lumière Lyon)

While standard models recognize intrinsic costs of lying, they typically treat reputational concerns as a calculation of external risk—trading off the benefits of lying against the probability of detection by an outside observer. We show that honesty oaths short-circuit this calculus and function by internalizing the audience, transforming the act of lying from a calculated transgression into a categorical identity violation. In a controlled experiment, we show that while the oath dramatically increases truth-telling, those who do break their promise systematically avoid brazen, detectable lies, retreating instead to ambiguity. Crucially, this refusal to be a “brazen renegade” persists even when the oath is private and compliance cannot be traced to the participant by the experimenter. This inelasticity rejects standard reputational models: instead, our data are consistent with the oath-taker answering to an internal judge rather than an external one. Furthermore, we show that this internal audience does not strictly require the cognitive amnesia or imperfect recall required by standard self-signaling models; rather, it can also be understood as a present-moment, categorical refusal to generate inescapable evidence of one’s own transgression. Finally, we show that investors intuit this mechanism, pricing in the oath’s “psychological enforceability” by granting credibility only when the speaker has no room to hide.

Aug 7

11:45 am - 12:00 pm PDT

Hierarchical Representations

Presented by: Milena Jessen (University of Bonn)

Evidence from cognitive science suggests that people organize multi-dimensional information into hierarchies, yet we lack causal evidence on how the hierarchical ordering of dimensions shapes learning and choice. I study this question experimentally. Participants learn success probabilities of firm–project pairs over multiple rounds and repeatedly choose the pair most likely to succeed. I exogenously vary whether outcomes are grouped by firms or by projects, inducing the grouped dimension as the top level of participants’ hierarchy while holding information constant. Participants process information conditionally on this top-level dimension: they form more accurate beliefs about summaries on it and locally optimize within it, while compressing information at lower levels. As a result, participants most accurately identify the best option within whichever dimension is placed at the top of their hierarchy – and these belief distortions translate into systematic choice distortions. Choice effects are stronger among low-attention participants, and procedural data confirm that participants process their top-level dimension first. Endogenous experiments demonstrate that individuals are not passive recipients of imposed structure: they adapt their representations to both cognitive costs and environmental diagnosticity.

Aug 7

12:00 pm - 12:15 pm PDT

Fragile Learning From Others

Presented by: Alisher Batmanov (University of California, San Diego)

Behavioral biases in decision-making are widespread and often persist even in the presence of feedback diagnostic of optimal behavior. This paper examines whether exposure to others’ decisions can correct initial misconceptions and facilitate learning in an environment where departures from the theoretical benchmark arise from neglecting an informative signal in a worker hiring task. Using a laboratory experiment, I show that exposure to optimal behavior substantially improves decision quality. The analysis of the underlying mechanisms suggests that this improvement is not driven by mechanical imitation alone, as subjects respond asymmetrically to the quality of observed choices, nor entirely by the richer feedback environment that social exposure generates. I then evaluate the retention and transfer of these learning gains beyond the period of exposure and find that, for most subjects, the improvements are fragile. Comparing the effects of social exposure to those of explicit guidance further underscores the limits of observational learning as a policy tool. These findings highlight the dual role of social learning: while it can enhance decision-making, it can also generate imitation behavior that fails to generalize beyond the observed context.

Aug 7

12:15 pm - 12:30 pm PDT

Designing Experiments to Distinguish Theories

Presented by: Cassidy Shubatt (Harvard University)

Baiyun Jing (Harvard University)

We develop an interpretable measure of an experimental design’s power to distinguish between a set of competing theories. A design offers a powerful test of a theory if competing theories would be unable to explain theory-consistent behavior on the design. We use the measure to analyze a set of the most highly-cited choice under risk experiments. We show that there is substantial variation in power across designs, and that power is consequential for determining which models best fit data. We then propose and implement an algorithm for constructing power-maximizing experimental designs. We show that our algorithmically-generated designs match or exceed the power of the best designs from the literature and require substantially less data.

Aug 7

12:30 pm - 2:00 pm PDT

Lunch

Aug 7

2:00 pm - 3:15 pm PDT

Session 3 (Chair: Manu)

Aug 7

2:00 pm - 2:30 pm PDT

The Hedonic Cost of Privacy: Information Avoidance under Entertaining Content

Presented by: Eleonora Freddi (Oslo Metropolitan University)

Aug 7

2:30 pm - 3:00 pm PDT

The Impact of Work Assignments on Evaluation and Advancement

Presented by: Lise Vesterlund (University of Pittsburgh)

Marissa Lepper (Texas A&M University) and Maria Recalde (The University of Melbourne)

This paper uses controlled experiments to examine how work assignments shape evaluation and career advancement. Workers are randomly assigned tasks of varying productivity, and evaluators observe their output, assess their relative performance, and make subsequent task assignment decisions. We find that workers assigned more productive tasks are paid more and evaluated more favorably. Evaluators systematically overattribute superior output to skill rather than assignment, producing inflated performance reviews and a tendency to keep initially advantaged workers on more productive tasks. In other words, early task assignments shape perceived ability and career trajectories, entrenching unwarranted disparities. Providing evaluators with more detailed performance information only modestly attenuates this bias. The documented path dependency in task assignment is particularly concerning in light of growing evidence that stereotyped perceptions influence how tasks initially are assigned within organizations.

Aug 7

3:00 pm - 3:15 pm PDT

The Female Labor Supply Constraints of Spousal Jealousy: Experimental Evidence from India

Presented by: Kailash Rajah (Stanford University)

This study presents evidence from two field experiments studying the role of spousal jealousy in constraining married women’s employment. In a first experiment (N =1, 400), I randomize married women in India to receive a two-week job in either a mixed or women-only workplace. Women randomized to the women-only workplace are 46% more likely to apply for a job (13 percentage points) and 31% more likely to turn up (6 percentage points). A cross-randomized safety treatment suggests that workplace safety is not the main mechanism. Instead, the treatment effects are significantly stronger among women who report having more jealous and controlling husbands. In a second experiment (N = 210), I directly test for a spousal jealousy mechanism by measuring whether women are more willing to interact with a male colleague if their husbands can monitor the interaction. I offer women a job that comes with a compulsory online peer support program and give them the option to forgo 20-35% of their salary to guarantee that the peer they are matched with will be a woman as opposed to a man. Fifty-three percent of women pay for the female peer when these remote interactions are one-on-one, but this drops to 34% once their husbands have the option of joining and can therefore monitor the conversations. One-third of households still pay for a female peer even if the mentoring simply involves watching prerecorded videos of the peer, suggesting even the most innocuous interactions are enough to raise jealousy concerns.

Aug 7

3:15 pm - 3:45 pm PDT

Coffee Break

Aug 7

3:45 pm - 4:45 pm PDT

Session 4 (Chair: Lise)

Aug 7

3:45 pm - 4:15 pm PDT

Psychedelics and Well-Being: An Experiment in Brazil

Presented by: Matt Lowe (University of British Columbia)

Patrick Francois (University of British Columbia), Ieda Matavelli (University of New South Wales)

We partnered with an ayahuasca center in Brazil to study the well-being effects of a one-time ayahuasca treatment within a ritualized group setting. The center enrolled 429 first-time ayahuasca users to participate in the largest randomized controlled trial of psychedelics ever run. Relative to placebo, ayahuasca increases happiness and reduces psychological distress six months later by roughly 0.4 standard deviations. The field experimental setting allows investigation of aspects not explored in the large clinical literature. Positive effects are almost entirely driven by participants that were distressed at baseline. Improvements in well-being are strongly positively correlated with the mystical nature of trips. The mystical experience can also be induced by placebo with ritual, though less frequently, and when done so induces a similar magnitude of well-being improvement. Effects are larger for older people, consistent with the idea that psychedelics reopen a window of heightened malleability. We estimate the mental health benefits of participating in an ayahuasca ceremony to be roughly 200 times the cost of 24 USD.

Aug 7

4:15 pm - 4:45 pm PDT

The Limits of Escalating Incentives: Evidence from Substance Use Treatment

Presented by: Ariel Zucker (University of California, Santa Cruz)

Rebecca Dizon-Ross (University of Chicago) and Corina Mommaerts (University of Wisconsin Madison)

Escalating incentive contracts — where rewards increase with success — are theoretically appealing and widely used in practice, including as the standard design in contingency management programs for substance use treatment. We show that the case for escalating incentives rests on three assumptions: forward-looking behavior, limited heterogeneity in compliance costs, and a principal objective that is not too concave. We test these mechanisms in a randomized experiment in which adults in treatment for opioid and stimulant use disorders are assigned to escalating, de-escalating, or constant incentives for drug abstinence. We find that while participants are forward-looking — which favors escalation — compliance costs are highly persistent both across and within individuals. This persistence generates a targeting disadvantage for escalating contracts: they concentrate the largest payments on those with the lowest compliance costs, where incentives are least needed. Escalating contracts also generate greater dispersion in compliance outcomes, which is costly when the principal places greater weight on reducing the worst outcomes. We estimate a dynamic structural model of compliance to characterize the optimal incentive schedule. We find that escalating schedules are preferred when the objective is sufficiently convex (prioritizing complete abstinence), while de-escalating schedules are preferred when the objective is linear or concave (prioritizing reductions in severe drug use). Our results suggest a rethinking of the widespread use of escalating incentives in substance use treatment.

Aug 7

5:00 pm - 7:00 pm PDT