Acton Institute Powerblog

The tragedy of the commons

Share this article:
Join the Discussion:

Note: This is post #63 in a weekly video series on basic microeconomics.

Common resources are nonexcludable but rival, says Alex Tabarrok in this video by Marginal Revolution University. For instance, no one can be excluded from fishing for tuna, but they are rival — for every tuna caught, there is one less for everyone else. Nonexcludable but rival resources often lead to what we call a “tragedy of the commons.” In the case of tuna, this means the collapse of the fishing stock. Under a tragedy of the commons, a resource is often overused and under-maintained. Why does this happen?

(If you find the pace of the videos too slow, I’d recommend watching them at 1.5 to 2 times the speed. You can adjust the speed at which the video plays by clicking on “Settings” (the gear symbol) and changing “Speed” from normal to 1.25, 1.5 or 2.)

Click here to see other videos in the Introduction to Economics series.

Joe Carter Joe Carter is a Senior Editor at the Acton Institute. Joe also serves as an editor at the The Gospel Coalition, a communications specialist for the Ethics and Religious Liberty Commission of the Southern Baptist Convention, and as an adjunct professor of journalism at Patrick Henry College. He is the editor of the NIV Lifehacks Bible and co-author of How to Argue like Jesus: Learning Persuasion from History's Greatest Communicator (Crossway).


  • Thanks for this Joe. Let me propose the following for some criticism and feedback. With the ITQ, the State does not give property rights to a certain tonnage of fish for this does not give the fisher ownership of some specific fish and there may not even be that tonnage of fish in existence. What the State does is authorizes the fisher to obtain a certain tonnage of fish. This authorization is itself property that can be exchanged, something like the way patents give authority to their owners over certain behaviors and can be traded.