Download The Tragedy of the Commons

The Tragedy of the Commons
The tragedy of the commons refers to how free access and unrestricted demand for a
finite resource ultimately structurally dooms the resource through over-exploitation. This
occurs because the benefits of exploitation accrue to individuals or groups, each of whom
is motivated to maximize use of the resource, while the costs of the exploitation are
distributed among all those to whom the resource is available (which may be a wider
class of individuals than that which is exploiting it).
The concept was popularized by Garrett Hardin’s essay in 1968 called the “Tragedy of
the Commons”; however, the concept has been around since the time of Aristotle who
said “that which is common to the greatest number has the least care bestowed upon it”.
In his essay, Hardin develops this theory with the use of a hypothetical common pasture
shared by local herders. The herders are assumed to wish to maximize their yield, and so
will increase their herd size whenever possible. The utility of each additional animal has
both a positive and negative component: Positive: the herder receives all of the proceeds
from each additional animal; Negative: the pasture is slightly degraded by each
additional animal. Crucially, the division of these costs and benefits are unequal: the
individual herder gains all of the advantage, but the disadvantage is shared among all
herders using the pasture. Consequently, for an individual herder weighing these, the
rational course of action is to add an extra animal, and another, and another. However,
since all herders reach the same rational conclusion, overgrazing and degradation of the
pasture is its long-term fate. Hardin draws links with this hypothetical situation to that of
the Earth’s resources being a general commons, such as the atmosphere, oceans, rivers
and fish stocks, which is being exploited by the ever increasing human population who
are each individually seeking to maximize their gains.
The Game:
Concept:
Students are introduced the idea of carrying capacity and the tragedy of the commons. In
this simulation, students desiring to draw renewable resources from a common pool
experience, by trial and error, how a shared resource can be depleted, and not all
individuals benefit equally, and ways in which individuals can maximize their gains
without depleting the common resources.
Materials:
Tokens (such as Popsicle sticks) – 10 per student
Candies of other rewards
Stopwatch or watch with a second hand
CD or tape player
CD of tape of lively music (at least 8 minutes worth)
Procedure:
Count out ten tokens for each student playing the game. Put one-fourth of them in a
separate pile.
Seat the students in a circle
In the center of the circle, place the pile comprising one-fourth of all the chips (for
example, if you have 4 students, you use 40 tokens, and begin with 10 in the center. If
you have 10 students, you use 100 tokens and begin with 25, and so on).
Read the following rules carefully to students. Allow time for questions and answers to
make sure students understand the rules of the game thoroughly.
Rules:
1. The tokens belong to all of you, to the group.
2. Music will be played, and while it is playing, each of you may take tokens out of
the pool of tokens in the center.
3. You may no put tokens back into the pool once you have taken them out.
4. Each of you may trade in 10 chips for a piece of candy.
5. As soon as the music stops, I will double the number of tokens left in the pool at
that time, and then continue the game.
6. There will never, however, be more tokens in the pool than there are at the start of
the game. This is the maximum number of tokens the pool can hold.
7. You may not talk to anyone during the game.
Notes to the leader:
Do not explain the significance of the tokens before playing the game. The rules are the
only instructions the players get.
The players will most likely completely empty the pool almost instantly the first time the
game is played. Point out that, as it’s impossible to double zero, the game is over. Ask if
they’d like to try again. Each student must return all of their tokens to the pool.
Continue to play the game for several rounds without giving the students time to
communicate with one another in between.
When doubling the tokens in the pool, remember there can “never be more tokens in the
pool than there are at the start of the game, this is the maximum number of tokens the
pool can hold.” Think if the tokens in the pool as fish, in a pond that only has enough
room and food to support as many fish (or tokens) as there were in the pool at the start of
the game. That number is the pool’s carrying capacity for tokens, and the pool is the
commons.
After that, ask students how they feel about the way the game worked out. As a group,
help the students think of ways they could cooperate to allow more of them to get their 10
tokens without depleting the pool of resources. Play again using these strategies
developed by students.
Discussion Questions:
1. What do the tokens represent? Renewable resources, such as fish or trees. (Coal,
gasoline, oil, iron, are examples of non renewable resources, and therefore aren’t
applicable in this exercise.)
2. Can we draw any parallels between the way the group treated the tokens and the
way individuals, and society as a whole, uses or overuses renewable resources?
DEFORESTATION: cutting trees down without planting replacements or at a
rate at which newly planted trees are not given time to grow to maturity before
they too are harvested; or cutting down old growth or tropical rainforests which
can never be replaced. OVERFISHING: taking so many fish that not enough are
left to reproduce and replenish the stocks for the next year. OVERFARMING:
depleting the soil of nutrients without giving it time to regenerate (Conversely, we
overwhelm nature by producing too much the rate at which we produce carbon
dioxide and other forms of pollution far outpaces the time required by air and
water to clean themselves).
3. How many tokens were taken out of the pool by each player in the different game
variations? How many candies did this generate? How did it make you feel about
other members of the group? This discussion question can be done after a few
rounds of playing without talking, where only a select few will have received
candies, and the others have received none of the benefits from the common pool
of tokens. Have those who received candies explain to those that did not why it
was OK for them to have candies at the others expense and vice versa to show
how the tragedy of the commons can maximize the gains of a few at the expense of
the group.
4. How did talking about the game make you play differently? After discussing the
strategies, did it seem differing attitudes were behind the ways in which you
played the game? Why did some participants take as many tokens as they could
reach and others leave some behind? How did this make you feel?
5. Have you experienced a similar situation at home, with friends, in your
community? How in the long run, can more benefit if individuals refrain from
taking too much? What sort of attitude do we need to have as individuals to
achieve the goal of the greatest benefit for all?
This game is based on an activity developed by Kurt and Ursula Frischknecht and Karen
Zimbelman in Thinking Globally and Acting Locally: Environmental Education Teaching
Activities by Lori D. Mann and William B Stapp, ERIC/SMEAC, 1982.