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SERGIU HART
cancer, and it’s an important way. Another way is simply to ask, what is cancer?
How does it work? Never mind curing it. First let’s understand it. How does it get
started, how does it spread? How fast? What are the basic properties of cells that
go awry when a person gets cancer? Just study it. Once one understands it one can
perhaps hope to overcome it. But before you understand it, your hope to overcome
it is limited.
H: So, the standard approach to war and peace is to view it as a black box.
We do not know how it operates, so we try ad-hoc solutions. You are saying that
this is not a good approach. One should instead try to go inside the black box: to
understand the roots of conflict—not just deal with symptoms.
A: Yes. Violent conflict may be very difficult to overcome. A relevant game-
theoretic idea is that, in general, neither side really knows the disagreement level,
the “reservation price.” It’s like the Harsanyi–Selten bargaining model with in-
complete information, where neither side knows the reservation price of the other.
The optimum strategy in such a situation may be to go all the way and threaten. If
the buyer thinks that the seller’s reservation price is low, he will make a low offer,
even if he is in fact willing to pay much more. Similarly for the seller. So conflict
may result even when the reservation prices of the two sides are compatible. When
this conflict is a strike, then it is bad enough, but when it’s a war, then it is much
worse. This kind of model suggests that conflict may be inevitable, or that you
need different institutions in order to avoid it. If in fact it is inevitable in that sense,
we should understand that. One big mistake is to say that war is irrational.
H: It’s like saying that strikes are irrational.
A: Yes, and that racial discrimination is irrational (cf. Arrow). We take all
the ills of the world and dismiss them by calling them irrational. They are not
necessarily irrational. Though it hurts, they may be rational. Saying that war is
irrational may be a big mistake. If it is rational, once we understand that it is, we
can at least somehow address the problem. If we simply dismiss it as irrational we
can’t address the problem.
H: Exactly as in strikes, the only way to transmit to the other side how important
this thing is to you may be to go to war.
A: Yes. In fact Bob Wilson discussed this in his Morgenstern lecture here in
’94—just after a protracted strike of the professors in Israel.
H: Here in Israel, we unfortunately have constant wars and conflicts. One of
the “round tables” of the Rationality Center—where people throw ideas at each
other very informally—was on international conflicts. You presented there some
nice game-theoretic insights.
A: One of them was the blackmailer’s paradox. Ann and Bob must divide a
hundred dollars. It is not an ultimatum game; they can discuss it freely. Ann says
to Bob, look, I want ninety of those one hundred. Take it or leave it; I will not
walk out of this room with less than ninety dollars. Bob says, come on, that’s
crazy. We have a hundred dollars. Let’s split fifty-fifty. Ann says, no. Ann—“the
blackmailer”—is perhaps acting irrationally. But Bob, if he is rational, will accept
the ten dollars, and that’s the end.
INTERVIEW WITH ROBERT AUMANN
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H: The question is whether she can commit herself to the ninety. Because if
not, then of course Bob will say, you know what, fifty-fifty. Now you take it or
leave it. For this to work, Ann must commit herself credibly.
A: In other words, it’s not enough for her just to say it. She has to make it
credible; and then Bob will rationally accept the ten. The difficulty with this is that
perhaps Bob, too, can credibly commit to accepting no less than ninety. So we have
a paradox: once Ann credibly commits herself to accepting no less than ninety,
Bob is rationally motivated to take the ten. But then Ann is rationally motivated
to make such a commitment. But Bob could also make such a commitment; and if
both make the commitment, it is not rational, because then nobody gets anything.
This is the blackmailer’s paradox. It is recognized in game theory, therefore,
that it is perhaps not so rational for the guy on the receiving end of the threat to
accept it.
What is the application of this to the situation we have here in Israel? Let me tell
you this true story. A high-ranking officer once came to my office at the Center for
Rationality and discussed with me the situation with Syria and the Golan Heights.
This was a hot topic at the time. He explained to me that the Syrians consider land
holy, and they will not give up one inch. When he told me that, I told him about the
blackmailer’s paradox. I said to him that the Syrians’ use of the term “holy,” land
being holy, is a form of commitment. In fact, they must really convince themselves
that it’s holy, and they do. Just like in the blackmailer’s paradox, we could say that
it’s holy; but we can’t convince ourselves that it is. One of our troubles is that the
term “holy” is nonexistent in our practical, day-to-day vocabulary. It exists only
in religious circles. We accept holiness in other people and we are not willing to
promote it on our own side. The result is that we are at a disadvantage because
the other side can invoke holiness, but we have ruled it out from our arsenal of
tools.
H: On the other hand, we do have such a tool: security considerations. That is
the “holy” issue in Israel. We say that security considerations dictate that we must
have control of the mountains that control the Sea of Galilee. There is no way
that anything else will be acceptable. Throughout the years of Israel’s existence
security considerations have been a kind of holiness, a binding commitment to
ourselves. The question is whether it is as strong as the holiness of the land on the
other side.
A: It is less strong.
H: Maybe that explains why there is no peace with Syria.
A: You know, the negotiations that Rabin held with the Syrians in the early
nineties blew up over a few meters. I really don’t understand why they blew up,
because Rabin was willing to give almost everything away. Hills, everything.
Without suggesting solutions, it is just a little bit of an insight into how game-
theoretic analysis can help us to understand what is going on, in this country in
particular, and in international conflicts in general.
H: Next, what about what you refer to as “connections”?