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From: carnes@gargoyle.UUCP (Richard Carnes)
Newsgroups: net.legal,net.politics.theory,net.auto
Subject: Re: Seatbelts for passengers (micromotives & macrobehavior)
Message-ID: <160@gargoyle.UUCP>
Date: Mon, 19-Aug-85 20:34:49 EDT
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Posted: Mon Aug 19 20:34:49 1985
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Mitch Marks writes:

>All the same, I'd like to propose another rationale in favor of the law, one
>which isn't respectable enough to make it as an official reason, but which
>is ultimately the real reason why I'm fer the law more than agin it.  All in
>all, I would rather wear a belt and be safe.  But (before the law) I would
>often feel silly -- like a nerdo wimp, you might say  -- or else, when a 
>passenger, feel like I'm insulting the driver.  "I'd better get this belt
>on quick, 'cause I know you're gonna crash us."  Okay, so with the law
>in place all these second thoughts and strange projections can just
>evaporate.  

Actually, this is a nontrivial reason in favor of such laws.  A law
can help change a collective behavior pattern in which all the
individual agents act rationally, yet the total result is far from
optimal.  For example:  everyone slows down to stare at an accident
on the freeway, and the result is a traffic jam in which every driver
spends ten extra minutes driving just to see an accident that each
driver individually would only want to spend ten extra *seconds* to
see.  Such patterns are common in interactions among people (they are
often called Prisoner's Dilemma or Free Rider situations), and in
general, individual rationality does not lead to a collectively
optimal situation.  The free market is a special case: the market
"works" (in the sense it may be said to work) because each agent
enters the marketplace *voluntarily*.  But this is not the general
case with social interactions.

In the case of a passenger (or driver, for that matter) who feels it
is "wimpy" or discourteous to use a seat belt in the absence of a
law, a law may change the situation as Mitch describes above, so that
for him using a belt is now the rational choice.  The result is that
at virtually no cost (since he is not being perceived as rude or a
wimp, and it takes ?1.5 sec to buckle up), he gets in return an large
increase in safety (50% reduction in chances of death or injury).
Multiply this by all drivers and passengers so affected, and the net
benefit to society would be large.  Furthermore, the same result
could obtain if a person is largely motivated by *habit* (which I
suspect is often the case WRT seat-belt usage) rather than social
norms that forbid wimpiness or discourtesy:  a law could provide the
situation that would change a person's habitual behavior at little
cost but great benefit to the individual.  But I'm speculating now.

An excellent book on this topic is Thomas Schelling's *Micromotives
and Macrobehavior*.  

Richard Carnes, ihnp4!gargoyle!carnes