Margin of Profit:
Many
years ago, I was
living in a part of Manhattan near Columbia University. When I
found it
necessary to go out at night I carried with me a four-foot
walking stick. My
friend Ernest Van den Haag argued that I was making a dangerous
mistake;
potential muggers would see my behavior as a challenge and swarm
all over me. I
responded that muggers, like other rational businessmen, prefer
to obtain their
income at the lowest possible cost. By carrying a stick I was
not only raising
the cost I could inflict on them if I chose to resist, I was
also announcing my
intention of resisting. They would rationally choose easier
prey.
I never did get mugged, which is some
evidence for my view.
More comes from observing who does get mugged. If muggers are
out to prove
their machismo, they ought to pick on football players; there is
not much glory
in mugging little old ladies. If muggers are rational
businessmen seeking
revenue at the lowest possible cost, on the other hand, mugging
little old
ladies makes a lot of sense. Little old ladies—and other
relatively defenseless
people—get mugged. Football players do not. It is said that when
someone asked
Willie Sutton why he robbed banks his answer was that that's
where the money is.
The economic approach to crime starts from
one simple
assumption: criminals are rational. A burglar burgles for the
same reason I
teach economics, because he finds it a more attractive
profession than any
other. The obvious conclusion is that the way to reduce burglary
is by raising
the costs of the burglar's profession or reducing its benefits.
The analysis that helped me decide what to
take with me on
my evening strolls around Manhattan's Upper West Side can also
be applied to a
point that comes up in arguments over gun control. Opponents
argue that gun
control, by disarming potential victims, makes it more difficult
for them to
protect themselves. Supporters reply that since criminals are
more experienced
in violence than victims, the odds in any armed confrontation
are with the
criminal. This is probably true, but it is almost entirely
irrelevant to the
argument.
Suppose one little old lady in ten carries a
gun. Suppose
that one in ten of those, if attacked by a mugger, succeeds in
killing the
mugger instead of being killed by him or shooting herself in the
foot. On
average, the mugger is much more likely to win the encounter
than the little
old lady. But, also on average, every hundred muggings produce
one dead mugger.
At those odds, mugging is an unprofitable business—not many
little old ladies
carry enough money to justify one chance in a hundred of being
killed getting
it. The number of muggers declines drastically not because they
have all been
killed but because they have, rationally, sought safer
professions.
When, as children, we learn about different
sorts of
animals, we imagine them in a strict hierarchy, with the
stronger and more
ferocious preying on everything below them. That is not how it
works. A lion
could, no doubt, be fairly confident of defeating a leopard, or
a wolf of
killing a coyote. But a lion that made a habit of preying on
leopards would not
survive very long; a small chance of being killed and a
substantial risk of
being injured is too high a price for one dinner. That is why
lions hunt zebras
instead.
In analyzing conflict, whether between two
animals, criminal
and victim, competing firms, or warring nations, our natural
tendency is to
imagine an all-out battle in which all that matters is victory
or defeat. That
is rarely if ever the case. In the conflict between the mugger
and the little
old lady, the mugger, on average, wins. But the cost of the
conflict is high
enough so that the mugger prefers to avoid it. In this case as
in many others,
the problem faced by the potential victim is not how to defeat
the aggressor
but only how to make aggression unprofitable. The logic of the
problem is
nicely summed up in Van Rijn's reply to one of his colleagues
who suggests that
they should fight even if it costs more than the trade is worth
to them:
"Revenge
and destruction are un-Christian thoughts. Also, they will not
pay very well, since it is hard to sell anything to a corpse.
The problem is to
find some means within our resources to make it unprofitable
for Borthu to raid
us. Not being stupid heads, they will then stop raiding and we
can maybe later
do business."
I
made this point, using a little old lady with a pistol in her
purse as my
example, in an economics textbook published in 1986. Eleven
years later John
Lott and David Mustard published an article offering statistical
evidence that
laws allowing concealed carry tended to reduce crimes, such as
rape or mugging,
that required the criminal to confront his victim. [1]
That set off a lively academic controversy, with statistical
articles
supporting and others contradicting Lott and Mustard’s result,[2]
and
a parallel political controversy. The result of the latter is
that ten states
currently permit concealed carry without a permit and thirty-one
have laws
requiring the authorities to issue a concealed carry permit
unless they have
good reason to withold it. Whether the result is more crime or
less is still a
question that people disagree about, with the division largely
along political lines.
Two men encountered a hungry
bear. One turned
to run. "It’s hopeless,” the other told him, “you can’t outrun
a bear.”
“No,” he replied "But I might be able to outrun you.”
[1]
John
R. Lott, Jr. and
David B. Mustard, “Crime, Deterrence, and Right-to-Carry
Concealed Handguns,” The
Journal of Legal Studies, Vol. 26, No.
1 (January 1997), pp. 1-68.
[2] I
followed the controversy
for a while on my web page with the assistance of John Lott
to point me at
articles supporting his position and Tim Lambert, a critic
of Lott’s argument,
to point me at articles on the other side. Eventually the
statistical arguments
reached a level beyond my competence to evaluate. For my
account of the early
stages, see:
http://www.daviddfriedman.com/Lott_v_Teret/Lott_Mustard_Controversy.html.