Prisoner's Dilemma

John K Clark (
Wed, 2 Jul 1997 20:08:09 -0700 (PDT)


On Mon, 30 Jun 1997 Michael Butler <> Wrote:

>I maintain that being able to determine the counterpart's past
>dealings with you is pretty darned close to "recognizing" the

You must know how to contact me, but you don't need to know my physical
location or know what I look like. You must know one of my names, but I could
have others. You might have dealings with 2 names with radically different
reputations and not know and not need to know that both are me. I might make
part of my money honestly and it's important that I have a good reputation
for that name so that people will know by examining my history that if make a
deal they will treated well. I might also make money as a flim-flam artist
selling perpetual motion machines, but I use a different name for that.
As long as you make a deal with the first name you're safe because it's
to my interest to maintain a good reputation for it.

On Tue, 1 Jul 1997 Kennita Watson <> Wrote:

>In a population of 10 people, if 9 play tit-for-tat and one always
>defects, the 9 will be defected against 10% of the time, and the one
>will be defected against 100% of the time. This isn't useful for
>producing descendants.

The tit-for-tat strategy is to always cooperate on the first transaction and
then do what your counterpart does. If the population is large then most
transactions will be the first encounter with an individual. This too is an
oversimplification of course.

John K Clark

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