Collective action in practice

The applied record. Most deliberate attempts at large-scale cooperation have failed; a few have worked, and the differences between them are legible.

Worked, partly worked, failed

• Montreal Protocol — the clearest success, and an unusually easy case
• Kyoto Protocol — the clearest failure of the same era
• Nuclear non-proliferation — partial, and still holding
• Fisheries collapse

What the difference turns on

Roughly the five questions of The collective action diagnostic: how many players, whether defection is observable, whether it can be punished, whether the players meet again, and whether anyone is large enough to act alone. Substitutes matter too — Montreal had them and Kyoto didn't.

Live cases

• Arms race — nuclear, and now AI
• Metacrisis
• Information commons