ARMS-D-Request@XX.LCS.MIT.EDU (Moderator) (06/18/86)
Arms-Discussion Digest Wednesday, June 18, 1986 3:39PM
Volume 6, Issue 111
Today's Topics:
An additional SDI problem: sensor technology
Prisoner's Dilemma Tournament
SDI, Processed World articles
Re: Saving 5% (;-]
RE: Third World Dictatorships
Prisoner's Dilemma and the Arms Race and the Foreign Policy
Economic Impact of SDI: Transcript Info
ERCS = "fail-safe" LOW?
No Nerve gas called Lance.
----------------------------------------------------------------------
Date: 16 Jun 86 16:44:43 EDT (Monday)
From: MJackson.Wbst@Xerox.COM
Subject: Re: An additional SDI problem: sensor technology
Jon Jacky writes:
"I can think of two reasons why this area has received relatively little
attention. First, there were no galvanizingly absurd statements about
sensors
from relatively prominent SDI proponents - nothing like James Fletcher
calling for "ten million lines of error-free code," or all that bizarre stuff
in the Fletcher report and elsewhere about launching pop-up X-ray lasers
under computer control. Second, there is a lot secrecy in the sensor area--
unlike battle management, where the important issues do not turn on classified
material."
Dare one suggest that the second reason might have something to do with the first?
Mark
------------------------------
Date: 7 Feb 86 10:08:45 PST
From: MEGIDDO@IBM-SJ.ARPA
Re: Prisoners' Dilemma
First Announcement of a
COMPUTER PROGRAMS TOURNAMENT
(of the Prisoners' Dilemma game)
1. INTRODUCTION
_______________
This is a first announcement of a tournament for computer programs,
playing the famous Prisoners' Dilemma game. Detailed instructions and
some background information are provided below. The tournament is
organized for the purpose of research and no prizes are offered. It
is intended however that the results and winners' names will be
published with permission from the persons involved. One of the goals
is to see what will happen during a SEQUENCE of tournaments in which
information about the participating programs will be released, so that
participants will be able to revise their programs. The tournament is
open to everyone. However, notice the warnings below. If you have
access to electronic mail then you can participate by submitting a
FORTRAN program according to the instructions below. By doing so you
will also release and waive all your copyright rights and any other
intellectual property rights to your program. It will also be assumed
that you have not violated any rights of any third party. This
announcement also includes some programs that will help you prepare
for the tournament.
2. BACKGROUND
_____________
The so-called prisoners' dilemma game has drawn the attention
of researchers from many fields: psychology, economics, political
science, philosophy, biology, and mathematics. Computer scientists
are also interested in this game in the context of fundamentals of
distributed systems.
The game is simple to describe, does not require much skill and is yet
extremely interesting from both the theoretical and practical points
of view. By the (one-shot) Prisoners' Dilemma game we refer to a game
as follows. The game is played by two players with symmetric roles.
Each has to choose (independently of the other) between playing action
C ("cooperate") or action D ("defect"). The scores to the two
players, corresponding to the four possible combinations of choices of
actions, are as shown in the following table:
Player 2
C D
---------------
| 3 | 4 |
C | | |
| 3 | 0 |
Player 1 |-------|-------|
| 0 | 1 |
D | | |
| 4 | 1 |
---------------
Thus, both players score 3 if both play C. Both score 1 if both play D.
If one plays C and the other one plays D then the one who plays C scores
0 while the other one scores 4.
The prisoner's dilemma game has been the subject of many experiments.
A tournament was organized several years ago by R. Axelrod who later
published a book on it under the title "The evolution of cooperation"
(Basic Books, Inc., New York, 1984).
Following is some discussion for the benefit of readers who are not
familiar with the fundamental considerations of how to play the game. One
should be careful to distinguish the one-shot game from the REPEATED game
in which the (one-shot) game is played many times, and after each round
both players are informed of each other's actions. Furthermore, one
should distinguish between the infinitely repeated game and the finitely
repeated one. These seem to be quite different from the point of view
of equilibrium. An equilibrium in a 2-person game is a pair (S1,S2) of
strategies (one for each player) such that, given that player i (i=1,2)
is playing Si , the other player, j=3-i, scores the maximum if he plays
Sj .
We are interested here in the finitely repeated game where the number
of rounds is known in advance. We first consider the one-shot game.
The analysis of the one-shot game is obvious. Each of the players
realizes that no matter what his opponent does, it is always better
for him to play D rather than C. Thus, under a very weak assumption
of rationality (namely, players do not choose actions that are
strictly dominated by other actions), the pair of actions (D,D)
remains the only rational choice. The resulting score of (1,1) is
inferior to (3,3), which is possible if the choices are (C,C), and
this is the source of the "dilemma".
To get some insight into the more general case, consider first
the 2-round game. After the first round (in which the players choose
independently C or D) each player is informed of the choice of the
other one and then, once again, the players choose independently C or
D. In this game each player has EIGHT strategies that can be coded in
the form XYZ where each of X,Y and Z equals either C or D. The
interpretation of this notation is as follows. (1) Play X in round 1.
(2) In round 2, play Y if the opponent played C and play Z if the
opponent played D. It is easy to verify that any strategy XYZ is
strictly dominated by XDD (that is, regardless of what was done in
round 1, and regardless of what the opponent does in round 2, it is
better to play D rather than C in round 2. However, there is no
domination relation between the strategies CDD and DDD: if player 2
plays DDD then player 1 is better off playing DDD rather than CDD,
whereas if player 2 plays DDC, player 1 is better off playing CDD
rather than DDD. Of course, strategy DDC for player 2 is dominated by
DDD, but in order for player 1 to deduce that player 2 will not play
DDC, he has to assume that player 2 is capable of discovering this
domination. Under such an assumption player 1 can eliminate 2's DDC.
Thus, if both players are "rational" they are left only with strategy
DDD as a reasonable choice.
A similar process of repeatedly eliminating dominated strategies
applies to the general N-round game. It is dominant for both players
to defect in the last round. Therefore (after we drop all strategies
that play C in the last round), it becomes dominant to defect in round
N-1, and so on. This eventually leaves both players only with the
strategy of always playing D.
The winner in both tournaments run by R. Axelrod was the simple
strategy called "Tit-for-Tat". It starts by playing C and in round i+1
plays whatever the opponent played in round i. It seems like a very good
strategy for playing the repeated dilemma for an indefinite number of
rounds. In the N-round game it is obvious that an improvement over Tit-
for-Tat would be to play Tit-for-Tat except for the last round in which
the optimal play is always to defect.
3. HOW TO PARTICIPATE IN THE TOURNAMENT?
________________________________________
If you think you understand the dilemma quite well and would like to
participate in this tournament then please act according to the following
instructions:
[Instructions are available from the ARMS-D moderator. They are long,
and involve writing a program to implement your proposed strategy.]
------------------------------
From: ucdavis!lll-crg!ihnp4!ihuxl!dcn@ucbvax.Berkeley.EDU
Date: Sun, 15 Jun 86 19:18:57 EDT
Subject: SDI, Processed World articles
SDI lasers & mirrors: Even if you can protect a reentry vehicle, satellite
or a whole booster from a laser, will it also be proofed against particle
beams, a `shotgun' blast, an X-ray laser and a direct kinetic impact? The
idea is that you can't protect everything against all types of attack, and
some part of the system will probably get you. Of course, overloading the
system will allow some to get through, and this is probably the easiest
defence to construct. Then it's a question of which technology is cheapest:
offense or defense.
Processed World articles on space: Of course astronomers want more
unmanned flights - that's how they get the majority of their data. Although
during Skylab flights, solar astronomers loved having someone in orbit with
the instruments to watch for solar activity. If you talk to other scientists
you would get different answers, depending on who gets the benefits of manned
flight. As far as space resources go, why shouldn't they be used instead of
messing up the earth? There may be a few places we want to protect, like
the lunar vacuum, Earth orbital debris, etc, but in general, there's no
ecology to spoil in open space. If we find life, then we can rearrange our
priorities.
The shuttle is partly our fault too. Where were you when the budget
battles were being fought, and NASA had to accept DoD involvement in order
to build anything at all? And when congress forced everybody to cut back
on unmanned boosters (leaving us heavily dependent on the shuttle), where
was the public support for NASA funding? Now that everyone knows what
happened, maybe we can get going again.
Dave Newkirk, ihnp4!ihuxl!dcn
------------------------------
Subject: Re: Saving 5% (;-]
Date: Tue, 17 Jun 86 13:08:43 -0800
From: Tim Shimeall <tim@ICSD.UCI.EDU>
>Date: 13 Jun 86 14:53:29 EDT (Friday)
>From: MJackson.Wbst@Xerox.COM
>Subject: Saving 5% (;-]
> ...
>Well, let's see. I think most Americans would agree that life in the
>Soviet Union was worth at least 5% of life in the US, and I doubt that
>anyone short of the extreme right-wing thinks the Soviets would
>slaughter more than 19 out of 20 after a takeover.
Sorry, even in jest I can't pass this up. I strongly dispute the
assertion that life in a Soviet-dominated US is worth 5% of life in
the current US, at least for me. Let's assume that I'm lucky enough
to escape the initial purges. In a soviet-dominated US, I would have
to give up:
- My intended career (use of computers would be heavily curtailed,
and teaching becomes a party monopoly)
- My leasure activities (travel is highly restricted, backpacking
forbidden to prevent defectors from escaping; microcomputers would
restricted to party members (if that); I don't know about Science Fiction,
but I strongly doubt it would continue except as disguised propaganda)
- My religion
Not much is left -- less than 5% of my time, and much, much less
than 5% of the things that make life worthwhile. I would suggest
that you think carefully before making blanket statements.
An interesting question, and one relevant to strategic discussions:
How much IS life worth in a soviet-dominated US, compared with the
current US? My answer is much less than 1%, but how about the rest
of you?
Tim
------------------------------
Date: Tue 17 Jun 86 18:55:21-EDT
From: Richard A. Cowan <COWAN@XX.LCS.MIT.EDU>
Subject: RE: Third World Dictatorships
From: Steve Walton <ametek!walton@csvax.caltech.edu>:
I'm afraid that Jeanne Kirkpatrick's distinction between
authoritarian and totalitarian regimes is both accurate and useful,
and submit as evidence recent events in the Phillipines and Haiti as
contrasted with the far worse repression in Vietnam, Laos, and
Cambodia. The latter group's governments have not, and will not fall
due to internal popular uprisings.
Perhaps I am wrong, but I suspect a double standard in the way you
define the "falling" of a government. When talking about the
governments of Vietnam, Laos, and Cambodia, I suspect you mean the
overthrow of socialism and/or the removal of these countries from the
Soviet sphere of influence. When talking about the Phillipines and
Haiti, you definitely mean the transfer of power without any change
in social system or sphere of influence. The difference is crucial.
Neither the Filipino nor the Haitian uprisings produced changes we'd
consider revolutionary if they happened in a USSR-backed country.
Even if Aquino has good intentions, the peasants who were exploited
under Marcos will not get substantially better standards of living
unless someone pays for it: the corporations who they ultimately work
for, the landowners in the Phillipines, or the American taxpayer.
This would be unlikely. And the Haitian "revolution" was accompanied
by cluster of US warships off the coast of that island to insure a
smooth transition to a less corrupt leader who would still guarantee
US interests. Both leaders were evacuated on United States planes.
I'm not willing to rule out a popular "revolt" in Soviet-backed
countries which simply has the outcome of installing a new puppet who
can sell the Soviet system more effectively to the people. And I
agree that the Soviet system is extremely repressive when threatened
by unrest within countries threatening to leave its sphere of
influence. But the United States is also repressive when countries
under its sphere of influence threaten to leave, as history has shown
time and time again in Latin America.
-rich
------------------------------
Date: Tue, 17 Jun 86 16:15:35 pst
From: mikes@prandtl.ARPA (Peter O. Mikes)
Subject: Prisoner's Dilemma and the Arms Race and the Foreign Policy
POM: I saw several worthwhile topics lately: the discussion of
the Game-Theoretic approach and Charlie's serious question
on "what can be done"?... I am not arguing with
following selected fragments of the past points; rather I
will attempt to summarize (or amplify?) them after ***** line..
>
> the nuclear arms race is in fact the Prisoner's Dilemma.
>Unfortunately, one or both sides do not seem to know the optimal
>long-term strategy (cooperation).
The above is far too simplistic.
Secondly, the real world is better modelled probabilistically. Thus, if
one pitted two realistic t/t's against each other, and not the pure ones
used in the referred to experiments, one of the two would at some point
randomly defect, leading to a bloody alternation of defection/cooperation
until one of them randomly called uncle and peace returns. Not very op-
timal, although it may be realistic.
Thirdly, existing threats are of variable and not always accurately per-
ceived credibility. Thus, your strategy might be very good in computer
simulation, but fail spectacularly if your opponent does not realize what
you are in fact doing and/or threatening. This point is similar to the
mutual ignorance mentioned near the beginning.
So why study these models? Do they tell us anything?
From: Clifford Johnson <GA.CJJ@SU-Forsythe.ARPA>
Both the U.S. and U.S.S.R. do understand the optimization problem.
Nuclear war, preceeding crises, conventional war, the President, the
USSR supreme command, the rest of the world, and so on, have all
been game-theoretically programmed for the DOD by the RAND Strategy
Assessment Center....
The message is, the administration does know, or have some objective
comprehension, of strategies optimal according to game theory, but
deliberately overrides them. I think this is important to
appreciate.
From: Steve Walton <ametek!walton@csvax.caltech.edu>
Subject: Third World dictatorships
Charles Crummer commented recently that we don't have a moral leg to
stand on (or words to that effect) if we continue to support
repressive regimes while condemning the Soviets for having one.
... the far worse repression in Vietnam, Laos, and Cambodia. The latter
group's governments have not, and will not fall due to internal
popular uprisings. Even Pol Pot (and before him, Hitler) was removed
only by externally applied force.
It certainly appears that the real problem is that the governments
which support us are not repressive enough. The ones which are are
nearly all regimes which call themselves socialist and are supported
by the USSR.
********************* comment / summary to the above ********** (by POM):
Q1 and 2: Is the 'brinkmanship' of the arms race indeed the
1) optimal AND 2) reasonable policy?
Optimal means "rational" in theoretical sense, while reasonable
means that 'a person'/ (you, nation) would actually do it. The paradox
of arms race indeed has a strong similarity to PD, simple or extended,
in creating the feeling that rational policy is somehow absurd.
R1: Response to feeling of absurdity is realisation that there must be
a better way, often felt as a deeply moral, humanistic or religious
issue. Charlies reasoning was an example of that, but I suppose that
lot of the Peace movement and freeze demonstrations are driven by the
similar reasoning and emotions.
R2: There is a reaction to the attemps to 'really go and talk to them',
based on experience, both past and present (treaty violations,
undisputed fact that soviet regime is repressive, often brutal. ...)
In this mode of thinking, the world is divided into 'our allies'
and 'their allies' and one half's gain is others loss,
- a zero sum game
- which indeed would evaluate any accomodation as a contra-
productive weakness, and lead logically to nothing else but use
of force, deterrence, ..and Steve Walton reaction, is an exemple of
that. There is really no argument with that, except, that it
leads back to Q1 and Q2 and feeling of absurdity and -- in sort of
the vicious circle - back to R1.
It looks that lot of debate on
US national policy is revolving in this type of circular paradox.
So?
What can I add to that, which was not already said many times?
I think I did tried to convey this before, and was either not
understood, not clear myself (or both)... I will try once more.
I think that position ( represented for simplicity by Steves point)
is valid, in its emphasis on strength and need for military
power on the part of the US. Important assymetry in the arms race is,
that US military power is under democratic control and there is an
open discussion on "how and when it should be used".
The Charlies position is also valid, in its implication that
technological approach is not enough. Ethical issues are also relevant.
I think it is the key issue in the whole arms-race paradox.
I believe that US, should maintain and build its military power, projecting
its image to the ouside. It does does that quite effectively.
I believe that in addition to that, US should build its moral argument and
project its image to the outside. And in this department, I am convinced,
there is a great space for improvement. I am not thinking about a propaganda
machine. However statement of actual principles, which US (and those other
nations, who may adopt that) considers as proper basis for dealings between
nations and actual observance of such principles, may transform the arms
race from a game of two 'selfish', 'rational' players ( which only admits
absurd solutions), into something which can, in the long run lead to a real
solution ( a system in which cooperative strategies are rewarded). The
example of Phillipines has shown that there are situations in the foreign
policy in which US government can act in a way which is ethical, sensitive
and in the long run expedient. All whats needed (to solve the arm race)
may be to make such an approach a policy - rather than a happy coincidence.
------------------------------
Date: Tue 17 Jun 86 19:47:52-EDT
From: Richard A. Cowan <COWAN@XX.LCS.MIT.EDU>
Subject: Economic Impact of SDI: Transcript Info
About 5 months ago I advertised a transcript/tape for a debate on
the economic implications of Star Wars, held at MIT on November 21, 1985.
Finally, I have uploaded it from my Mac, and it is available online.
The debate is between:
Lester Thurow, MIT Economist
Leo Steg, GE Space Systems Division (retired)
Bernard O'Keefe, Chairman of EG&G
For FTP'ing it, it is located in MIT-XX:<cowan>economics.sdi
If you can't FTP it, tell me and I'll send it to you.
-rich
------------------------------
Date: Saturday, 14 June 1986 16:55-EDT
From: Clifford Johnson <GA.CJJ at SU-Forsythe.ARPA>
To: arms-d
Re: ERCS = "fail-safe" LOW?
> I don't think that ERCS would be used to support LOW. By
> assumption, LOW is before anything in the US is destroyed, so why
> use such a kludgy system to do that?
Ball, and others, have called ERCS "silly" and "gimmicky."
Do you think they are *not* a kludgy system?
My answer is yes and no. From the military-realism standpoint, in
the event of a *surprise* attack, ERCS are more survivable than all
the other systems taken together, which the Soviets could snuff
within 5 minutes. This arises from ERCS heartland location. It's
the decapitation scenario, and SLBMs versus the capability to launch
ERCS is the battle, and, concurrently, SLBMs versus the capability
for the NCA to say GO. In these circumstances, a first SLBM barrage
(simultaneous detonation) would plainly include high altitude
airbursts (=EMP) and follow-ons over Whiteman. It's a desperate
get-the-message-out-before-detonation mission, and ERCS by that
yardstick measures up better than other means of message
disemmination.
ERCS are in a sense more secure message disemminators than other
channels, being overland in the U.S. and then "physically" carried
to the subs. Does this mean that some of them would have an
important first-strike/preempt role?
To: LIN@XX.LCS.MIT.EDU
------------------------------
From: inmet!brianu%ima.UUCP@CCA.CCA.COM
Date: Wed, 18 Jun 86 13:52:45 edt
Subject: No Nerve gas called Lance.
The neurotoxin Lance does not exist. It is merely the product of a
case of escalating paranoia. In 1977 a drug addict told a Killeen, Tx.
policeman that someone on the streets was cutting herion and cocaine
with a poison called "Lance". The Killeen police department
alerted the Arizona Customs Services to be on the look out for these
cut drugs. The Arizona Customs alerted the St. Louis Customs which
published a warning that customs agents should not even open bags of
narcotics because Lance was so deadly.
Next, the alert was sent to the Rochester, NY customs office,
which aleted the U.S. Postal Service that the Lance packets might be
sent through the mail, and any found should be forwarded to Customs
officals unopened. The Postal service circulated an internal memo to
this effect, which was picked up by the FDA. The FDA alerted
government officals that they may receive packets of Lance in the
mail and to be careful.
This caused the Multnomah County Board of Commissioners to issue
to statement that County officals had been warned to be on the
lookout for Lance, which was being mysteriously mailed to goverment
offices, and was a powder, like talc, that would instantly kill
anyone tasting it and would cause irreversible brain damage if it
was merely smelled.
The Oregon Journal decided to check out the story, and traced it
back to its origins. It published the whole story on Feb. 3, 1977.
By two days later the FDA, the Postal Service and the U.S. Customs
Service had all repudiated their warnings.
There is an actual product called Lance. but it is a commercially
available crowd-control substance.
====================================================================
Gen.: And do you mean to say that you would deliberately rob me of
these, the sole remaining props of my old age, and leave me to go
through the remainder of life unfriended, unprotected, and alone?
Pirate: Well, yes; that's the idea.
Brian Utterback Intermetrics Inc.
733 Concord Ave. Cambridge MA. 02138. (617) 661-1840
UUCP: {cca!ima,ihnp4}!inmet!brianu
Life: UCLA!PCS!Telos!Cray!I**2
------------------------------
End of Arms-Discussion Digest
*****************************