1.  The tragedy of the commons symbolizes the degradation of the environment that is expected to occur whenever many individuals use a scarce resource in common. It is simply depicted by the following image.

“Each man is locked into a system that compels him to increase his herd without limit – in a world that is limited.” Hardin, 1968.

Ostrom stresses that much of the world is dependant on resources that are subject to the possibility of the tragedy of the commons (i.e. overfishing, pollution of air, land, rivers, overuse of energy, food, etc.)

2. The prisoner’s dilemma illustrates the paradox that individually rational strategies lead to collectively irrational outcomes which challenges that fundamental principle that rational human beings can achieve rational results.

The “prisoner’s dilemma” depiction to the left is a simple illustration of the game theory that explains how individuals choose strategies (to cooperate or to defect) and how the dominant strategy is always to defect, no matter what the other player chooses. Hence, self interest dominates over common interest.

3. The logic of collective action is that individuals with common interest would voluntarily act so as to try to further those interests and achieve thei r common goal (Olson, 1965). However, Olson challenged the presumption that the possibility of a benefit for a group would be sufficient to generate collective action to achieve that benefit. Olson posits that unless there is coercion of some other special devise to make individuals act in their common interest, rational, self-interested individuals will not act to achieve their common or group interests.