Recommended shortlist

Cut from the 176 candidates. The full lists stay as a research database — this is what to actually use, and each entry says what job it does.

Criteria

Scored on, in rough weight order:

Teaches a mechanism, not an outcome. About two-thirds of the candidates are outcomes. "Everyone overfished and the fish died" is an anecdote; "the wintering rule replaces an unmeasurable quantity with one every neighbour verifies for free" is a move you can reuse.
Structural distinctness. The set must span prisoner's dilemma, coordination and assurance, subtractable commons, positive commons, threshold goods and arms races.
Is it felt. A case has to land before the formalism means anything.
Scale distinctness, and pairing across scales.
Evidential safety. A contested case costs two minutes of caveat with this audience, worth paying only for a uniquely good mechanism.
Cuts against priors. This audience knows Moloch and knows the tragedy of the commons. Overturning an assumption beats confirming one.
Reuse across modules, and balance — the course is about opportunities as much as failures.

The spine — six that carry the course

If a Tree Falls (already chosen, prep viewing) — activists who solved a hard cooperation problem for years, then informed on each other within weeks of arrest. S1.

Bank runs and Diamond–Dybvig — the purest coordination failure, structurally unlike a prisoner's dilemma: two equilibria, and which one you get depends only on what each depositor expects everyone else to expect. Deposit insurance fixes it by deleting an equilibrium, not by improving anyone's character. Carries the dilemma/coordination/assurance distinction, which is the one that does real work. Photographs, and a 90-second film scene that explains the whole mechanism. S2, S4.

Törbel's wintering rule — no more cows on the alp than you can winter on your own land. Counting grass eaten on a shared alp is impossible; counting a neighbour's hay barn in February is free, and everyone in a village of 600 does it as a side effect of living there. Observability engineered into the rule itself. The best single mechanism in the whole set, and uncontested. S3.

Montreal / Kigali / leaded petrol / CFC-11 — one slot, four cases, run as a controlled comparison rather than a success story. Montreal worked on an easy problem (few producers, cheap substitutes, a trade ban that bit). Kigali is a climate agreement that worked, because it was shaped like an ozone agreement — which kills "climate is intrinsically harder". Leaded petrol was phased out globally with no treaty at all, isolating substitutes as the operative variable. CFC-11 is observability tested live: the violation was caught from the atmosphere, not from anyone's reporting, and stopped within two years. S4.

Fork-tailed drongo false alarm calls — a bird that free-rides on an alarm system's credibility, and escalates to mimicking meerkat calls once its own stop being believed. An arms race, in a bird, on film. Best-filmed cheating case that exists. S1, S3.

Dictyostelium cheater strains — a free rider with no cognition, no intention, no culture and no morality. The strongest available support for the course's central claim that defection is not a deficiency, because there is nobody there to be deficient. Independently evolved again in Myxococcus, which makes the point twice. S2.

High value, distinct jobs

The trench truces — repeated play with the diagnostic running visibly: cooperation appeared where units faced each other for months and could observe each other, and died the moment command rotated units and forced raids. Axelrod already treats it, so theory and case arrive together. S3.

The Great Stink (1858) — sanitation went unprovided for twenty years while everyone agreed it was needed, and was funded in about three weeks once the smell reached Parliament. A failure that got solved, and the cleanest statement that nobody was a villain — the cost simply sat in the wrong place. Public domain cartoons. S1 opener candidate.

Philosophical Transactions and the invention of priority (1665) — dated publication turned giving a discovery away into the way to claim it. A selective incentive bolted onto a public good, 300 years before Olson named the move. Fills the undersupply half of the commons distinction, which is otherwise nearly absent from the whole candidate set. S3.

Anglo-German naval race + the Washington Naval Treaty — as a pair. The textbook arms race, and then the same structure actually solved, with a countable, observable unit as the mechanism. S1, S4.

The frontier AI race — the audience's live case, and distinctive because participants state the trap openly in their own founding documents. S1.

The Limited Test Ban Treaty (1963) — the scope of the agreement was set by what could be verified unilaterally. Atmospheric tests leave fallout; underground tests didn't show up, so they were left out. Detection technology determined what could be agreed, not trust. Pairs directly with Schelling. S4.

Meerkat sentinels — recommended because the standard telling is wrong. Guards are well-fed, in a safe spot, first to flee, with zero deaths in 2,000 hours of observation. A lesson in how readily we read altruism into a structure that doesn't need it. S3.

Balinese subak and the water temples — coordination rather than dilemma, with ritual as the synchronisation device. The bridge case: it belongs to Ostrom's material and prefigures session 5's argument that ritual is a cooperation technology. Lansing's account is contested (Helmreich); the case stands, the strength of the mechanism is what's disputed. S3, S5.

Mix and balance

Orca wave-washing (or musk oxen) — a threshold public good that cannot be produced alone, and a wordless opening image. Orca has the better footage; musk oxen make the threshold point more sharply, since a half-formed ring is worse than none. S1, S3.

Los Angeles groundwater basins — Ostrom's own dissertation and the empirical root of polycentricity, which is otherwise the most abstract module in session 4. Hundreds of independent pumpers, nested rather than centralised. S4.

Wikipedia and the open source maintainer problem — the same positive-commons structure, one working and one failing. Every firm depends on the infrastructure, none pays. The audience lives inside this one. S3, S4.

The liberum veto — a unanimity rule adopted for good reasons, which destroyed a state. Institutional design as the cause rather than human nature, which is a useful corrective in a course that could otherwise read as being about character. S2, S4.

The Danish rescue, October 1943 — the course needs at least one case of people doing the right thing at real risk, without organisation or leadership. Worth keeping the honest caveats attached (light occupation, paid passage). S5.

Deliberately not recommended

Rapa Nui, Norse Greenland, the Ik, the Donner Party. The four most memorable-sounding cases in the whole set, and the four weakest evidentially. Rapa Nui and Norse Greenland are exactly the Moloch-flavoured collapse narratives the course intends to argue with — usable only as case studies in how collapse stories get selected.

The commons-depletion long tail — cod, anchoveta, bison, passenger pigeon, Aral Sea, Dust Bowl. Six cases teaching one lesson. Pick one, probably cod for recency or bison for the images, and keep the rest in the database.

Kyoto on its own. Only teaches inside the controlled comparison above.

Additions from the warfare and fiction hunts

Both gaps are now filled, and the material is strong enough to displace some of the above. These are the promotions.

Warfare — the mechanisms of cohesion

The syssitia (Spartan common messes) — three cheap mechanisms stacked. Daily compulsory attendance makes absence instantly observable to the fifteen men who will stand beside you in the line. A fixed food contribution is a recurring costly signal, with loss of citizenship as the penalty for failing it. Admission is by unanimous ballot, so every member has been vouched for individually by every other. This is the direct answer to "what did it take to make hoplites". It also carries its own bill — the quota required land, and land required helots, which feeds S5. S3, S5.

The tresantes (Spartan "tremblers") — the sharpest case in the entire set for a problem nothing else covers: who punishes the punishers. A death penalty has to be administered by someone and is over quickly. Social death is administered by everyone, at zero cost, continuously, by exactly the people whose regard the sanction runs on. Plutarch's report that Agesilaus let the laws "sleep for a day" after Leuctra is the tell that it only worked while the numbers were small. S3.

Decimation and the fustuarium — two mechanisms usually conflated. The fustuarium conscripts the punishers: the condemned man's own comrades do the killing, so enforcement costs the state nothing and implicates them in it. Decimation deliberately severs guilt from punishment by drawing lots, and what that buys is collective liability — since you may die for your neighbour's flight, you now have a reason to stop him running. S3, S4.

The hoplite shield wall — each man's shield partly covers the man to his left, so the line is a public good that collapses if anyone runs: mutual hostage-taking plus total observability. Thucydides (5.71) on the rightward drift of advancing phalanxes is the evidence that individual incentives pull against the formation even while it holds. S1, S3.

The Plataean breakout (Thucydides 3.20-24) — the unexpected find. Counting bricks in the enemy wall by having many men count independently is aggregation substituting for measurement. Roughly half the men who agreed to go lost their nerve at the moment of escape — and because they did, the escape got safer for those who went. Free riding that helps is rare enough to be worth a slide. S1, S3.

Krentz's casualty ratio — losers roughly 14%, winners roughly 5%, in Greek hoplite battle. The quantitative statement of why the line holds: almost all the dying happens after it breaks. Pairs with Caporetto for the same phenomenon two millennia later. S3.

Fiction — clips that stand alone

Dr. Strangelove, the War Room doomsday-machine exchange (~5 min) — the characters explain the theory inside the scene: a commitment device must be automatic and announced, and a secret one is worthless. Almost certainly the highest-value clip in the course for the Schelling module, which is the module the AI-interested part of the audience is coming for. S4.

Norma Rae, the UNION sign (~3 min) — a threshold cascade rendered almost without dialogue, in sound, as the machines shut off one by one. The cleanest success available as a clip, and S1 needs one early. S1, S3.

Twelve Angry Men, the secret ballot (~4 min) — a mechanism deliberately designed to break an information cascade, shown working. S2, S3.

Battleship Potemkin, the firing squad — silent, public domain, and it plays to an audience that has never heard of 1905. S1.

What these displace

The list is now around 24, which is too many. I'd cut the liberum veto (the institutional-design point is made better by decimation, where the rule creates the incentive rather than destroying one), the Danish rescue (Norma Rae carries "people acted at real risk" better as a clip, and with a mechanism attached), and one of Anglo-German / Washington Naval — keep the pair only if S4 has room, since Dr. Strangelove now does the commitment-device work more vividly.

That lands at 20.

Notes on the fiction list

Four entries — Thucydides, Xenophon, Things Fall Apart, The Plague — are marked prep reading rather than in-session material, since no usable footage exists. Weak fits are flagged as weak: Jaws has no defection in it and is better used as the shape of a climate argument than as a game; The Dark Knight ferries is closer to mutual deterrence with a deadline than a strict prisoner's dilemma. Two structures came back genuinely thin — commons collapse as plot (fiction wants a villain and a commons failure has none, so documentary serves better) and coordination without communication.

Expanding any of these

Each entry names its structure, so "more like this one" is answerable from the full lists: more observability-by-design → the zanjeras, Alanya rotation, iriai synchronised harvesting. More positive commons → Republic of Letters, IGY mirrored archives, the UPU. More arms races → July Crisis, New START expiry, NPT. More cheating-in-nature → cleaner wrasse, Pseudomonas, acacia parasite.