Tragedy of the Commons
The tragedy of the commons is overuse of a rival, non-excludable resource because each user internalizes the benefit and shares the depletion cost.
Definition
A pasture open to all is grazed to ruin. The general object is a common-pool resource: rival in use, costly to exclude. Ostrom showed communities sometimes govern them without privatization or Leviathan. Financial analogues: a shared liquidity pool, a crowded factor, a payment system.
Why it matters
Crowded trades and shared collateral pools are commons. Each fund ‘rationally’ adds size; the exit door is finite.
Case
Quant crowdedness in 2007, meme-stock locates, and a stablecoin reserve that everyone treats as instant liquidity are commons problems. Hardin’s fatalism is optional; Ostrom’s rules are the research program.
How to read it
Is the resource rival? Can you exclude? If yes and no, you have a commons. Then ask what rule (price, quota, reputation) rations it.
Key papers
Landmark references with real publisher or arXiv links — not token-overlap noise.
- The Tragedy of the CommonsHardin · 1968 · ScienceThe popular statement — read Ostrom as the correction.