Time Spent in Airports:  Is that the way to go?

      Milton Friedman is reported to have said that a person who has
never missed an airplane flight has probably spent too much time in
airports.  To be pedantic about it, what he was saying was that the
inconvenience of a single missed flight is probably overbalanced by
the accumulated inconvenience of all those hours unproductively
spent in airports making sure to be on time.  

      If, for example, the person he is talking about were to arrive
at airports on average fifteen minutes later than had earlier been
his practice, he would gain 25 hours for every hundred flights he
takes, and that's practically a gain of a week's work.  If gaining
those fifteen minutes didn't lead to the missing of a single plane,
the new regime is pure gain.

      In that case, he ought perhaps to try arriving twenty minutes
later, rather than fifteen.  This would gain him 33 hours for every
hundred flights, a gain of 8 hours over the fifteen minute choice,
but now perhaps his courting of danger might have caused him to miss
a flight.  Was the cost of the missed plane worth 8 extra hours of
pointless boredom?  Maybe not.  Maybe he gets an hour-later flight
to the same destination, where the time of arrival was not crucial
to begin with, so that he's still ahead of the game.  In that case
he should so modify his habits so that it is practically certain he
will miss one plane out of a hundred.  Indeed, maybe he should
arrive half an hour later than he used to, gaining 50 hours for each
hundred flights?  That gains him 17 hours over the twenty-minute

      The question then is, how many more planes will he then miss? 
Maybe now it comes to four or five flights, that is, three or four
more than the one he would have missed by the fifteen-minute modifi-
cation of his previous behavior, and a really serious inconvenience. 
No; he'll stick to twenty minutes.  Or twenty-two.  The point is
that somewhere in that range there is a time-saving whose value is
such that trying to increase it by even one minute would result in
extra plane-missing whose pain is more than equal to the value of
the time saved.  That one minute saving (a hundred minutes, for a
hundred flights, actually) must be balanced against -- not the total
distress of all missed airplanes -- but the distress added to that
total by airplanes missed on account of that extra minute.  One
calls that minute the "marginal" return to the traveller, for his
decision to arrive later, and one calls those extra missed flights,
caused by that marginal return, the marginal cost of his changed
habit.  Once the marginal cost equals the marginal return, he should
stop changing his habits.  Arriving earlier at airports costs him
time worth more than the extra flights he doesn't miss, and arriving
later grants him time worth less than the pain of the extra flights

      To make this calculation one does not have to figure totals. 
How many airplanes he misses by his current habit, and how much time
he saves by it (over what he used to do when he came very early)
doesn't matter.  Once we know that the more airplanes you miss the
worse off you are, and the more time you save the better off you
are, the time you choose to save or spend depends only on the
marginal cost of time equalling the marginal cost of the resulting
missing of airplanes.  And what Milton Friedman assumed about human
behavior was as simple as this:  that people prefer more comfort to
less, and prefer smaller costs to larger.  And what he assumed about
airplane flights was this:  That coming late enough will miss all
the flights, so that whatever time is spent going to airports is all
lost, even if a large part of it is saved by coming late.  Saving
even a lot of time is clearly not worth it, if you miss all your
flights; and spending unnecessary time is also not worth it, even if
such behavior guarantees no missed flights at all.  These are
reasonable assumptions.

      In his dictum Friedman assumed one more thing, which was that
the man he was talking about never missed an airplane.  What did
that mean?  It meant that he was spending time, but receiving for it
an unknown degree of comfort.  He hadn't yet tested the marginal
cost and marginal return.  He did not know whether saving an extra
minute would have cost him a single missed airplane.  Not until you
reach a state when you can balance one against the other will you
ever know for sure that you aren't wasting your time.  And while it
is clear that, since you have so far missed no planes, you are
arriving (if anything) too early, what is not clear is whether you
are arriving late enough.  Thus the word "probably" in the Friedman
dictum.  Perhaps -- but only perhaps -- arriving one second later,
adding up to a hundred seconds, or less than two minutes total time
saved, will cause you to miss another airplane, with resulting
inconvenience more painful than losing those two minutes.  Then you
are already at equilibrium, but Professor Friedman, with his "proba-
bly", indicates that he has his doubts about that.

      Of course, Milton Friedman, Nobel Laureate in economics, was
talking about more than airplanes when he coined this illustration
of the principle of marginal cost and marginal return.  There are
graphs and formulas that express the things that have been described
above, and the economics books are filled with them.  And they are
necessary if one is to go on to more subtle considerations of
economic behavior, where there is more than one thing to spend your
time on, and more than one thing to spend for what you want, and
more than one person worrying about these things, and more than one
time at which exchanges take place, and other complications of a
different sort, such as price and wage levels, foreign exchange
rates, interest rates, government regulations and the danger of war
or pestilence.  

      But one must begin with simplicity before one can introduce
complexity and still keep track of the principles involved.

      This last comment is much misunderstood by the public, which
looks on economics as an inexact science, untrustworthy because it
begins with principles so simple that they don't correspond to the
complexity of the real world.  "Oh yes," the all-knowing columnist
will write, "That's all very well in theory, but in the real world
it doesn't work that way.  What about the poor?  What about racism? 
Friedman may be a brilliant man, but we out here know how unpredict-
able human nature is.  If you laid all the economists out end to end
they still wouldn't reach a conclusion."  Armed with this wisdom he
goes on the urge us all to Buy American, or he presses for price
controls on the cable television monopoly, secure in the belief that
his own sympathy for the downtrodden produces better answers than
Friedman's brilliance can.

      This is a misreading of the use of simple models, and probably
a willful misreading of what economists claim for their science. 
That columnist's attitude, that "we in the real world understand
things better than your theorists do," is well calculated to estab-
lish distrust of other things Mr. Friedman has said, many of them
less agreeable to his prejudices than commentary on airports.  
Looked at closely, that columnist's contention is that his own
slapdash conclusions on a complicated economic question are more
trustworthy than the Friedman's careful arguments built up out of
simpler models.  

      The principle of marginal cost measured against marginal gain,
so brilliantly exemplified in Mr. Friedman's metaphor of the air-
port, applies to every part of the economic world.  It applies --
and this is where the homespun philosopher-columnist really sees red
-- to the political and artistic worlds as well, where "cost" and
"gain", as metaphors for non-monetary measures of some sort, can
yield calculations of marginal values quite as illuminating as in
the domains of airport management and wage rates.  But before this
"economic approach" can affect the popular consciousness, and
produce useful results in either private taste or public policy, it
must be understood.  Which means that it must be taught.

      In this regard there are hopeful signs, which were not present
when I first encountered economic doctrines, fifty years ago. 
Everyone is today acquainted with technology that did not exist at
that time, and especially with "feedback mechanisms", of which there
were very few in those days: thermostats, "governors" of the speed
of motors, and the floats that monitor the refilling of water
closets come to mind as early examples.  What they have in common is
that they use the result of their own action to guide their subse-
quent action.  Thus when a thermostat, having been set high, has
told the furnace to heat the house, that very heat switches the
thermostat to the position that turns the furnace off.  Today,
devices of this sort are omnipresent in electronic appliances and
computers, including computer programs themselves, and are under-
stood in principle by a very large public, a much larger fraction of
the public than could have understood Adam Smith's metaphor of "the
invisible hand" in the 18th Century.  For that invisible hand is
nothing but the action of a similar mechanism that operates among
people as a whole.

      Another hopeful sign has been the visible collapse of the
socialist experiment in every land that has tried it.  More than
this, the social conditions that favored belief in the socialist
ideal are also no longer with us.  The Twentieth Century opened with
two forms of naivete‚ that are no longer present at its end:  

      The first was the aristocratic tradition of nobility, royalty
and status, which still had power to allocate wealth regardless of
economic productivity, and with the agreement, by and large, of a
cowed populace still trained to obedience.  This tradition is now
dead, and would continue to be dead even if it were shown that
royalty and aristocracy made for an efficient economic system. That
won't happen now, for we all now understand the relationship of
production and prosperity.  Not only does nobody take seriously the
notion that some classes of people are by accident of birth owed
deference -- and wealth -- by others, but our rewards to labor, and
deference to excellence, from farmer to concert violinist, are today
seen to be the natural fruits of production, not station.  Where
socialist revolution was thought by many a century ago to be the
only way to end the allocation of rewards to the unworthy, today it
may be seen that the market does it better.

      For the second naivete‚ of 1895 was the belief, among compas-
sionate social thinkers undeceived by the religious and aristocratic
cant of the time, that socialist doctrine was the inescapable
companion to the anti-aristocratic stance.  Today the whole world
understands that planning committees won't work, and guaranteed
income is guaranteed mismanagement.  The world's blessings may not
be reserved for a hereditary few, but it is now understood that it
also cannot be assigned by statutes, however well-intentioned.

      That the doctrine of the invisible hand has more chance to be
understood today than ever before is visible in the increasing
rejection of statist politics in democratic nations, and the freeing
of the market even in countries that have a long way to go before
achieving much liberty in other domains.  Even democracy brings the
danger that the fifty-one percent will merely pass laws dispossess-
ing the other forty-nine; but the experience of those nations that
have tried dispossession argues against it.  Whether done democrati-
cally or by revolution, whether according to the theories of Mao,
Peron, or Clement Atlee (all calling themselves socialists), the
results have disposed the world's population and its present leaders
to look skeptically on "soaking the rich", and on Five-Year Plans in

      One thing lacking in the public's preparation for good econom-
ic understanding is mathematics.  Economics is, like physics, a
mathematical science.  It would be nice if everyone could understand
physics, as C.P. Snow dreamed; but it won't happen and there's an
end on it.  It is, on the other hand, essential that the public
understand certain elements of economics, for otherwise even a
democratic decision can some day lead again to disastrous policy, as
it has in the past -- in Peron's Argentina, for example.  We are
only for the moment safe from both socialism and heriditary aris-
tocracy, because of the memory of recent experience.  That memory
will fade.  In other parts of the world, North Africa, for example -
-  we are still not safe from theocracy, largely because it has been
so many generations since those nations in danger have actually
experienced it.  

      In the West, and in the Far East, we have recent experience to
give us a breather:  socialism will not soon be tried again here. 
But if we do not teach our children the elements of economics that
breathing space will end.  Since the elements of economics require a
few basic mathematical concepts beyond the simple arithmetic that
has for four thousand years been the standard equipment of the
average educated man, a small revolution in the teaching of mathe-
matics is therefore also needed.  Required for this is far less than
what is needed to understand even the rudiments of physics, and that
is fortunate.  But though what is needed can be accomplished in the
elementary grades, and is much easier to understand, when well
taught, than the poetry of Robert Browning, which we do affect to
teach in the schools, we have not yet arrived at the necessary
school curriculum even in principle.  It will be found, however, and
I'll leave the matter right there for now.

      One should, finally, say a word about the economists' notori-
ous failure to reach a conclusion, even when laid end to end.  Or
the famous lament of Harry Truman, that he could not find a one-
handed economist, the ones around him being forever given to saying,
"On the other hand."  How can one argue that economics is a science
when economists cannot even "predict" last year's Gross National
Product, let alone next year's?  This of course is a matter of
confusing two things about a science:  its understanding of nature,
and its ability to process large amounts of information.

      A good analogy is Newtonian mechanics, indeed the very simple
laws governing falling and bouncing solid objects here on earth. 
Nobody would argue that physicists are unable to understand the laws
governing force, acceleration, velocity, friction, rotation and the
like, for solid bodies like rocks.  Astronomers using Newton's laws
can predict eclipses a thousand years in advance, and engineers can
tool gears to accomplish the most intricate geometric transforma-
tions imaginable, in the very bowels of our hard-used Fords and

      But let us put a physicist at the top of a hill somewhere, a
hillside covered with stones, bushes and trees, maybe some anthills,
gopher holes and a rivulet:  then give him a rock and a machine that
drops it at some precise point of his own choosing, with initial
velocity and rotation of his own choosing; then ask him to predict
where that (irregular) rock will end its roll down the hill.  

      You will not get the answer, though you give him a year to
measure all the details of the configuration of the rock and of the
hill.  Is it that he doesn't understand physics, or that physics is
too primitive to deserve the name of science?  No; it is only that
in this particular problem the data is too voluminous.  But this is
not what the columnist says, who has a bill of goods to sell.  "Even
the brilliant Professor Feynman, Nobel Laureate, cannot agree with
his colleagues on where the rock will come to rest," our columnist
will write, "Some science! Don't listen to these guys from the ivory
tower," he says; "Listen to me."

      (One might think that so ludicrous a stance, which has been
invented here only as a parable for what is always being said about
economics, would convince nobody, but the sad truth is that even
physics is today under the kind of attack one would expect only for
sciences with political implications. The reader is referred to
Gross and Levitt, Higher Superstition, Johns Hopkins Press, 1994,
for the story of some of the newer forms of anti-intellectualism.) 

      Now the physical and life sciences are to a large degree pro-
tected from ignorant attack by their obvious usefulness.  There are
chemicals that cure pneumonia, even among people who have no under-
standing for science, or respect.  When it comes right down to it,
the democratic majority will not destroy the biological laborato-
ries.  Nor will those who claim that all science is "socially
constructed", and that its truths are merely contingent or meaning-
less, throw themselves off cliffs on the grounds that gravity is
merely a postulate.  And they travel to conferences on "The failure
of the 'scientific method'" on airplanes designed by the dupes of
Isaac Newton.  Economic science is in a different case.  

      Adam Smith had the answer to Lenin's experiment a hundred and
fifty years before Lenin, but Lenin's experiment ran seventy years
just the same.  Seventy years of apalling misery buttressed by lying
tyranny.  But this was not because only experience could prove them
wrong.  From Von Mises to Schumpeter to Hayek and Friedman, econo-
mists attempted to explain the source of the disaster, but were
countered every step of the way by those who claimed to know better,
and who announced, besides, that these so-called economists were
really ivory-tower dreamers or paid tools of the Vested Interests.

      If there had been a public literacy in economics comparable to
the public literacy regarding the claims of blue blood and royalty,
we might have escaped all this.  In 1918 royalty was being struck
down in Germany and the Austrian and Russian empires, but it was not
always replaced with something more sensible.  A better general
economic literacy now reigns in those countries, but at what horri-
ble cost!  Perhaps, with a very little mathematical education of a
sort our elementary schools are not yet acquainted with, we can
generate such a literacy in lands that have not suffered the social-
ist experiment.  The United States, for example.  

      It wouldn't take much, and I am willing to outline such a
program, but that is for another place.  It is sufficient here to
say, briefly and I hope hopefully, that any person able to under-
stand the Friedman dictum about spending time in airports already
has the mathematical sophistication needed to formulate and follow
the economic argument that -- had it been understood by the rest of
the world -- would have saved us all from Lenin and Mao.

                                          Ralph A. Raimi
                                          October 13, 1995