When humans overuse a natural resource

When the short-term, positive effects go to the individual, while the long-term, negative effects are spread out to the group

When humans act selfishly, thinking of their own self-interest

When plants and animals compete for space, resources, and/or food

Overfishing and earthquakes

Flooding and tsunamis

Pollution and overpopulation

Super-germs and virus outbreaks

William Forster Lloyd

Garrett Hardin

Both a and b

Neither a and b

"The rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another, and another … Therein is the tragedy"

"Among the savage nations of hunters and fishers, every individual who is able to work is more or less employed in useful labor, and endeavors to provide... the necessaries and conveniences of life, for himself, and such of his family or tribe"

"There is one and only one social responsibility of business–to use it resources and engage in activities designed to increase its profits so long as it... engages in open and free competition without deception or fraud"

Improving literacy among urban populations

Raising tax rates for large corporations

Inventing stronger antibiotics

Passing a law to set limits for fishermen

Common house hold items like knifes, spoons, and forks.

A renewable resource owned by no one and available for use by anyone at little or no charge

A field where college students can sit outside in between classes