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A rational strategy of the prisoner's dilemma is an open-and-shut case. And that had been giving lots of researchers gloom.
Due to folk theorem it's been known that "Cooperation" is the key to create a world of wealth. However, that seems to be realized under purposely designed condition in the real world. For an example, competitor companies realize goal through collaboration in order to get a larger market share and a larger circulation.
"A rotten apple spoils the barrel" as the saying goes, that's used for the human society though, is it always the truth? If it's not, what factor could be effective?
The famous tournament of Robert M. Axelrod polarized opinion.
It seems determinate criticism that the result depends on the initial values. However, Axelrod is a pioneer. Binmore recognized him for creating awareness it's important to select a specified equilibrium among countless equilibriums.
The software introduced at this page is a simulator of the iterated prisonner's dilemma.
Sixteen strategy patterns due to four bits codes do the arms race. Sixteen ones were not arbitrary selections but systematic samplings.
It has couple of observation rules which are reference data for the strategies.
As we will discuss in detail later, each individual player could observe opponent's forpassed cards or own memory of opponents' cards, or could evaluate opponent's strategy codes, opponent's stats of all forepassed cards, opponent's stats of ethical estimations of all forepassed cards. And each player would decide the card cooperation or denial due to own strategy pattern.
The observation rule is an abilitiy of each individual.
It adopts a geometric rule in order to meet and play with an opponent in random order. Each individual does game with a neighbor opponent selected in random. In case not founded, an individual would move to a random toward. And in case of both sides have a certain vital level they would do cross-reproduction.
In the initial phase, cause the world resource is affluence and plentiful, individuals would get bonus points just due to game and would procreate one after another. In this initial phase a random chance would make a large influence.
It's impossible to predict what equilibrium would be selected. It seems to be the sport of slight haphazards on such a systematic and superficial simulator. However the direction of the equilibrium selected would be exposed to view due what ability(the observation rule) would be given.
For ver.0.86, some additional rules were added. Those were supposed as metaphars of the social world. In each case, it's possible to choice or not.
One is dealing with between two of a kind. Individuals could do game or crossing in case of they have similarity of their genes, due to set a percentage of same bits of the gene.
Another is refusing to deal with, the rich refuses to deal with the weak. Individuals could not do game nor crossing in case of a large disparty, due to set the ratio of vital scores. However, an individual could copy the strategy(gene) of the rich in case of the ratio is in among certain ratios. That's the imitative learning. A reason of limitation of ratios is that the influence is few in case of too much disparty.
For ver.0.87 one observation rule was added. It's estimation of opponent's strategy codes which is named Rule-X preseted. It's just like an observational ability of opponent's real nature.
As for other observation rules which observe few forpassed cards, those do not include informations of opponents of that moment, it's impossible to know opponent's real nature.
In concrete, it just evaluates opponent's strategy codes which is also opponent's sign expression though, as a social simulation, it might be a kind of the inspiration.
For ver.0.88 further two observation rules were added. One Rule-Y refers opponent's stats of all forepassed cards. Another Rule-Z refers opponent's stats of ethical estimations of all forpassed cards.
Rule-Y observes the records of opponent's count of forepassed C-cards and count of forepassed D-cards, and evaluates the ratio of those. That's supposed to be an bureaucratic record.
Rule-Z observes the records of opponent's count of ethical behaviors and count of unethical behaviors, and evaluates the ratio of those. That's supposed to be an intuition, although I wonder what metaphor is such an insight.
What ability should be given for what equilibrium could be emerged? -- That's the keynote of the simulation and let us know how to emerge a wealth of the world.
Try to run it at first please.