An open pasture ends up grazed to the dirt: everyone has an interest in adding one more animal, no one has an interest in sparing it. This is the tragedy of the commons. A shared, free-access resource tends to be overused, because the profit is private and the damage collective.
1 What is the tragedy of the commons?
When each one's interest ruins the good of all.
Definition
A free-access resource, overused to exhaustion
The tragedy of the commons describes a situation where a shared, free-access and limited resource is overused until it degrades. The image comes from the biologist Garrett Hardin (1968): a common pasture where each herder, acting rationally for himself, adds one more animal, until the field is destroyed for all. The word “tragedy” is meant here in its Greek sense: a fatal outcome, written into the very logic of the situation.
2 The mechanism
A private profit, a shared cost.
Why it goes wrong
①
The gain is private. Whoever exploits the resource reaps all the benefit.
②
The cost is shared. The degradation, by contrast, spreads across all users, present and future.
③
No one has an interest in holding back. Restraining oneself alone does not save the resource but forgoes the gain: restraint is punished, excess rewarded.
This imbalance has a name in economics: a negative externality. The actor does not factor into its calculation the harm it causes others, because nothing makes it pay. As long as access stays free and the damage costless, overuse is the logical outcome, not an accident.
3 From ocean to orbit
The same logic, at every scale.
🐟Fishing
Stocks emptied faster than they renew.
🌍The atmosphere
Each one emits; the climate degrades for all.
🛰️Low Earth orbit
Each satellite crowds the shared space; debris becomes a common risk.
🌲Forests, aquifers
Free-access resources, exhausted for want of a rule.
The orbit case
Low Earth orbit is a textbook case: a finite, free-access resource where each satellite launched brings it closer to saturation, even to a runaway of collisions, the Kessler syndrome. The launch's benefit is private; the debris risk weighs on all operators and on all generations to come.
4 The remedies
To escape the tragedy is to change the calculation.
Three families of solutions
①
Price the use. Make the cost imposed on others payable, a “Pigouvian tax.” For orbit, an orbital-use fee: economists estimate it could quadruple the sector's value over time.
②
Define rights. Allocate quotas, tradable permits or clear ownership, so each one factors scarcity into its calculation.
③
Govern in common. The work of Elinor Ostrom (Nobel Prize 2009) shows a community can sustainably manage a commons through shared, monitored rules, without privatising or nationalising everything.
One point matters: technology alone is not enough. Cleaning up debris without correcting the incentive to launch is like bailing a leaking boat. As long as polluting the commons stays free, we keep doing it.
5 Takeaways
What to remember.
✓
The tragedy of the commons: a shared, free-access and finite resource tends toward overuse.
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The cause: private gain, collective cost, an externality no one pays.
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From fishing to orbit, it is the same mechanism.
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The remedies: price the use, define rights, or govern in common (Ostrom). Technology alone is not enough.
This notion sheds light on an analysis
First published: 14 June 2026