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From: carnes@gargoyle.UUCP (Richard Carnes)
Newsgroups: net.politics.theory
Subject: Re: The free market
Message-ID: <237@gargoyle.UUCP>
Date: Thu, 7-Nov-85 19:02:39 EST
Article-I.D.: gargoyle.237
Posted: Thu Nov  7 19:02:39 1985
Date-Received: Sat, 9-Nov-85 07:25:39 EST
Reply-To: carnes@gargoyle.UUCP (Richard Carnes)
Organization: U. of Chicago, Computer Science Dept.
Lines: 48

Me:
>>[The point] is to show that one cannot simply add up individual decisions
>>and assume the total to be a simple sum of the decisions; at some
>>threshold the aggregate consequences may negate the individual's
>>intentions...

JoSH:
>So what else is new?  [quotes Adam Smith on "invisible hand"]

What is new is that Schelling describes, analyzes, and classifies the
situations in which macrobehavior is more than a simple sum of
micromotives.  I especially recommend Chapter 7 of *M&M* ("Hockey
Helmets, Daylight Saving, and Other Binary Choices").  This chapter
deals with binary choices in which one's choice affects either the
choice or the reward (payoff) of others.  Examples are:  keeping your
dog leashed or not, voting yes or no on ERA, staying in the
neighborhood or moving out, joining a boycott or not, carrying a gun
or not, driving with headlights up or down, getting vaccinated or
not, etc.  Multi-person Prisoner's Dilemmas are a common class of
situations that can arise from such binary choices with
externalities.  Chapter 7 explains "Schelling diagrams" for the
analysis of such collective action situations.  This chapter is not
especially long or difficult, but it greatly clarifies one's
understanding of collective action problems.  Sample quote:
______________

Shortly after Teddy Green of the Bruins took a hockey stick in his
brain, *Newsweek* (October 6, 1969) commented:

  Players will not adopt helmets by individual choice for
  several reasons.  Chicago star Bobby Hull cites the simplest
  factor:  "Vanity."  But many players honestly believe that
  helmets will cut their efficiency and put them at a
  disadvantage, and others fear the ridicule of opponents.  The
  use of helmets will spread only through fear caused by
  injuries like Green's -- or through a rule making them
  mandatory.... One player summed up the feelings of many:
  "It's foolish not to wear a helmet.  But I don't -- because
  the other guys don't.  I know that's silly, but most of the 
  players feel the same way.  If the league made us do it,
  though, we'd all wear them and nobody would mind."

The *Newsweek* story went on to quote Don Awrey.  "When I saw the way
Teddy looked, it was an awful feeling.... I'm going to start wearing
a helmet now, and I don't care what anybody says."  But viewers of
Channel 38 (Boston) know that Awrey did not. --T. Schelling
-- 
Richard Carnes, ihnp4!gargoyle!carnes