Download The Tragedy of the Commons - Appoquinimink High School

. . . and other sad tales
Once upon a time, there was a
lovely village
With a lovely commons where
the sheep grazed . . .
Happily . . . and produced happy
wool. And the village was happy.
And happy sheep made great
wool.
But as more and more sheep
joined the commons
The Commons was overused.
The grass ran out.
and tragedy ensued.
The sheep suffered.
And eventually the sheep
produced no wool at all. Brrrr.
Understanding the problem . . .
• Say 10 owners each turned out 10 sheep to graze in
a commons that has a carrying capacity of 100
sheep.
• As long as the owners don’t exceed the carrying
capacity, each sheep fleece will bring $100 in the
market, or $10,000 total.
• But if one owner decides to add 1 extra sheep, the
carrying capacity of the commons has been
exceeded and all the sheep will suffer
• For the owner of 11 sheep, his revenue will be
greater. That single owner gains.
• However, the total value of the sheep for all owners
will fall. The whole group loses.
What did the villagers miss?
• The villagers should have known that the
“Commons” was a common resource.
• As such, it was a rival good, meaning that one
person’s (or sheep’s) use diminished another’s
enjoyment of it.
• Common resources are always subject to
overuse--people (and sheep) are, after all,
MAXIMIZERS.
Other tragedies of the commons:
Ocean fishing
Bluefin Tuna Decline
1995 – 2012 (projected)
Buffalo nearly became extinct by 1900.
What prevented their extinction? More
importantly, why have cattle never been
threatened with extinction?
Other common resource tragedies:
• Carolina Parakeet- Eastern US’s only
parrot
• Blast fishing in the Tongan Islands
• The Amazon rainforests
In every decision we must consider the
impact on the next seven generations
-The Iroquois Confederacy
Last of the species died
in the Cincinnati Zoo in
1918.
Every minute 149 acres of rainforest are cut
down.
Blast Fishing not only decimates
fish populations but destroys the
habitats as well.
McDonald's at one time was importing 15
million pounds of this type of fish (Hoki). It
is now at around 11.5 million.