3. Go directly to gaol
The conductor of an orchestra in the Soviet Union (during the Stalin era) was
travelling by train to his next engagement and was looking over the score of
the music he was to conduct that night. Two KGB officers saw what he was
reading and, thinking that the musical notation was some secret code,
arrested him as a spy. He protested that it was only Tchaikovsky’s Violin
Concerto, but to no avail. On the second day of his imprisonment, the
interrogator walked in smugly and said, “You’d better tell us all. We have
caught your friend Tchaikovsky, and he’s already talking.”
So begins one telling of the Prisoner’s Dilemma, perhaps the best
known strategic game.* Let us develop the story to its logical conclusion.
Suppose the KGB has actually arrested someone whose only offence is that he
is called Tchaikovsky, and are separately subjecting him to the same kind of
interrogation. If the two innocents withstand this treatment, each will be
sentenced to 3 years’ imprisonment.† If the conductor makes a false
confession that implicates the unknown “collaborator,” while Tchaikovsky
holds out, then the conductor will get away with 1 year (and the KGB’s
gratitude), while Tchaikovsky gets the harsh sentence of 25 years for his
recalcitrance. Of course, the tables will be turned if the conductor stands firm
while Tchaikovsky gives in and implicates him. If both confess, then both will
receive the standard sentence of 10 years.
Now consider the conductor’s thinking. He knows that Tchaikovsky is
either confessing or holding out. If Tchaikovsky confesses, the conductor gets
25 years by holding out and 10 years by confessing, so it is better for him to confess. If Tchaikovsky holds out, the conductor gets 3 years if he holds out,
and only 1 if he confesses; again it is better for him to confess. Thus,
confession is clearly the conductor’s best action. In a separate cell in
Dzerzhinsky Square, Tchaikovsky is doing a similar mental calculation and
reaching the same conclusion. The result, of course, is that both of them
confess. Later, when they meet in the Gulag Archipelago, they compare
stories and realize that they’ve been had. If they’d both stood firm, they’d
both have got away with much shorter sentences.
If only they’d had an opportunity to meet and talk things over before
they were interrogated, they could have agreed that neither would give in.
But they are quick to realize that at in all probability such an agreement
would not have done much good. Once they were separated and the
interrogations began, each person’s private incentive to get a better deal by
doublecrossing the other would have been quite powerful. Once again they
would have met in the Gulag, there perhaps to settle the score of the
betrayals (not of the concerto). Can the two achieve enough mutual
credibility to reach their jointly preferred solution?
Many people, firms, and even nations have been gored on the horns of
the Prisoner’s Dilemma. Look at the life-or-death issue of nuclear arms
control. Each superpower liked best the outcome in which the other
disarmed, while it kept its own arsenal “just in case.” Disarming yourself
while the other remains armed was the worst prospect. Therefore no matter
what the other side did, each preferred to stay armed. But they could join in
agreeing that the outcome in which both disarm is better than the one in
which both are armed. The problem is the interdependence of decisions: the
jointly preferred outcome arises when each chooses its individually worse
strategy. Could the jointly preferred outcome be achieved, given each side’s
clear incentive to break the agreement and to arm itself secretly? In this case
it needed a fundamental change in Soviet thinking to get the world started on
the road to nuclear disarmament.
For one’s comfort, safety, or even life itself, one needs to know the ways
to get out of the Prisoner’s Dilemma. And there are ways.
The story of the Prisoner’s Dilemma also carries a useful general point:
most economic, political, or social games are different from games such as
football or poker. Football, poker, and tug-o’-war are zero-sum games: one
person’s gain is another person’s loss. But in the Prisoner’s Dilemma there
are possibilities for mutual advantage as well as conflict of interest; both
prisoners prefer the no-confession result to its opposite. Similarly, in
employer-union bargaining, there is an opposition of interests in that one side
prefers low wages and the other high ones, but there is agreement that a
breakdown of negotiations leading to a strike could be more damaging for
both sides. In fact such situations are the rule rather than the exception.
Any useful analysis of games should be able to handle a mixture of conflict
and concurrence of interests. We usually refer to the players in a game as
“opponents,” but you should remember that on occasion, strategy makes
strange bedfellows.