NetLogo User Community Models
tragedy of the commons v4_2
by Young Joon Oh (Submitted: 06/11/2014)
## TRAGEDY OF COMMONS MODEL By Young Joon Oh
This model is made in Nov. 2 . 2010 by Young Joon Oh at UT Dallas
When actors >= 2 and they should share the resource, they abuse the resource because of actors' selfishness. In the end, the resource gets exhausted.
Once the common has begun to be destroyed, it gets worse not only in the collective level, but in the individual level.
To solve this problem, collective action is needed.
For simulation of Tragedy of Commons(ToC), it is very important to depict some factors as follows ;
(1) Re-growing grass
(2) Generating and Consuming Energy of Sheep and Grass
(3) Selfish Shepherds
So, if a sheep's cumulative energy = 360, it means the sheep already has enough energy to live for 1 year. From 360 to the basic energy,35, the sheep do not need to get more energy from grass. This is called 'Full'.
When 'regulation' is operated, the whole common will be divided by 4 parts.
## HOW TO USE
- Input - number : the initial number of each sheep
- Slider - criterion : the criterion of healthy sheep
- Switch - bring-new : if on, the shepherds can bring new sheep
- Switch - sheep-y, sheep-b, sheep-r : if on, yellow, blue, and red sheep will appear
- Switch - regulation : if on, each kind of sheep can be fed on its own grasses
Llewellyn L. Manske, Grass Growth in Height, http://www.chaps2000.com/bin/ch2r3.pdf
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