Environmental Engineering Reference
In-Depth Information
Player 2
I
~I
10
-1
I
10
11
Player 1
11
0
~I
*
-1
0
Figure 10.9
Adaptation of a prisoner's dilemma structure game for
erosion restoration/prevention investments in common pool
scenarios
degradation and soil erosion af ecting the already low living standards of
people living in those areas.
Consider an area with a high degree of land erosion. Erosion can depend
on natural factors such as rainfall patterns, wind and topography but can
also result from human activities such as deforestation, clearing for cul-
tivation, overgrazing, extensive fuel wood cutting, and so on. Erosion in
turn af ects the productivity of the natural resource base. The negative
impacts of erosion can be ameliorated by investments in the common
property land such as af orestation, the construction of diversion ditches,
ridge banking, de-stocking, and so on. The implementation of these activi-
ties would provide joint benei ts for all users; however, problems of provi-
sion can arise with free-riders benei ting from the resource without having
contributed ef orts towards these activities.
Recall that provision problems in CPRs can be modelled, depending on
provision technology, with the prisoner's dilemma or with the assurance
game, the former having no one contributing to resource provision and the
latter having players contributing if, and only if, the others are to contrib-
ute. These two games are illustrated in Figures 10.9 and 10.10.
The individual proi ts from realizing the investments are the individual
benei ts derived from the investment, minus the costs incurred in the
investment, including the opportunity costs of time devoted to the activity.
Realization of these investments will depend on having the l ow of money
or resources required for realizing the investment, but will also depend on
what an individual thinks other members of the village will do.
Consider the payof s and strategies of Figure 10.9. Two dif erent
