Algorithms
A few weeks ago, for some
reason that now escapes me, I began to wonder what kind of president Al Gore
would make. Never mind his character or his private life--I leave such matters
to the experts. What I'm interested in is his mind. After all, Gore--like
Clinton--is an unusually bookish politician, one who reads serious tomes on
serious subjects and even tries to be a bit of an authority himself. Clinton's
pre-presidential intellectual tastes played a big role in determining the shape
of his administration's first couple of years. The same might be true of his
loyal lieutenant. And so I picked up a copy of Gore's 1992 environmental
manifesto, Earth in the Balance: Ecology and the Human Spirit . I can't
pass judgment on the scientific merits of the book's environmental analysis,
but Gore touches on areas where I do know something and, in so doing, he gives
me some important clues to his intellectual style.
Perhaps
the best way to think about Gore the thinker is to contrast him with Clinton.
Both men are deeply wonkish, clearly enjoying nothing (well, almost
nothing) more than long discussions on how to save the world with a simple
22-point program. But the objects of their affections differ. Clinton is most
attracted by matters social and economic, Gore by matters environmental and
scientific. Clinton is the kind of guy who attends panel discussions at
Renaissance Weekend and pores over the New York Review of Books . Gore
pays personal calls on physicists and curls up with Scientific American .
And while Clinton, before Bob Rubin took him in hand, was a rather credulous
consumer of pop economics, Gore's corresponding vice seems to be pop
science.
Which is not to say that Earth in the Balance is
entirely free from pop econ. The book contains a chapter, lamentably titled
"Eco-nomics," that perpetuates the oddly popular myth that conventional
economic theory is constitutionally incapable of dealing with environmental
problems. "Many popular textbooks on economic theory fail even to address
subjects as basic to our economic choices as pollution or the depletion of
natural resources," Gore declares. Actually, I have all the leading
introductory texts on my shelf (I'm writing one myself and am trying to steal
my competitors' ideas), and every one has an extensive section on environmental
issues. One looks in vain in Gore's book for even a mention of the fundamentals
of standard environmental economics: pollution as the prime example of an
"externality" (a social cost that the market does not properly value), and the
standard recommendation that externalities be corrected with pollution taxes or
tradable emission permits. (I wrote about the economics of environmentalism in
Slate
last year, in "Earth in the Balance Sheet.") Since these concepts have
actually made their way from theory into practice, one wonders how he missed
them. The introduction of tradable permits was an important feature of the 1990
revision of the Clean Air Act, for example, and both fees and permits have been
crucial in efforts to protect the ozone layer.
But for
me, at least, the really revealing part of Earth in the Balance was the
book's conclusion, where Gore talks about sandpiles and how they changed his
life.
Sandpiles, for those unfamiliar with pop
science trends, are the motivating example for a concept known as
"self-organized criticality," which, in turn, is one of the Big Ideas of
so-called "complexity theory." Imagine allowing sand to slowly trickle onto an
existing pile. Bit by bit the pile's sides will become steeper. When they
become too steep--when they exceed some "critical" slope--there will be an
avalanche. In simplified computer models of sandpiles (though not, apparently,
in all real sandpiles), a curious pattern emerges. Because the slope of the
sandpile is always close to its critical value, dropping a single grain of sand
on the pile can produce anything from no effect to a massive sand slide.
Specifically, the distribution of avalanche sizes follows a particular
mathematical form known as a "power law" that is found in many natural and some
social phenomena, such as the sizes of earthquakes and the sizes of cities.
(For an example of the power law applied to city size, click .)
What Per
Bak, the Danish physicist who came up with the sandpile metaphor, has argued is
that because sandpile-type models produce power laws, and because there are
lots of power laws out there in the real world, such models hold the key to
understanding, well, everything. Bak's book explaining this idea is modestly
titled How Nature Works . The reaction of his colleagues, as best I can
tell, is that the sandpile model is interesting, as is the prevalence of power
laws, but that his claims of having developed a universal theory are a bit
premature. (For more on power laws, click .)
If you are wondering what all this has to do with saving
the planet, congratulations. But here is what Gore, who made a pilgrimage to
see Bak, has to say:
The sandpile
theory--self-organized criticality--is irresistible as a metaphor; one can
begin by applying it to the developmental stages of a human life. The formation
of identity is akin to the formation of the sandpile, with each person being
unique and thus affected by events differently. A personality reaches the
critical state once the basic contours of its distinctive shape are revealed;
then the impact of each new experience reverberates throughout the whole
person, both directly, at the time it occurs, and indirectly, by setting the
stage for future change. Having reached this mature configuration, a person
continues to pile up grains of experience, building on the existing base. But
sometimes, at midlife, the grains start to stack up as if the entire pile is
still pushing upward, still searching for its mature shape. The unstable
configuration that results makes one vulnerable to a cascade of change. In
psychological terms, this phenomenon is sometimes called a midlife change.
This may
sound silly, and it is. But it is a time-honored kind of silliness. Gore is in
the grand tradition of those who thought that Einstein's theory of relativity
refuted not only classical physics but also conventional morality; or those who
imagined that because quantum mechanics showed that the apparent solidity of
the material world is an illusion, it vindicated the thoughts of Eastern
mystics. In the end, these particular confusions don't seem to have done the
world any harm. So why not let Gore find solace in sandpiles?
One answer is that the speed with which
sexy-sounding scientific ideas get picked up by popular culture is getting
alarmingly high: from Physical Review Letters to the latest best seller
by Tom Peters almost before you know it. This is arguably starting to distort
the practice of science itself. As geologist Nathan Winslow puts it in a gently
skeptical review on self-organized criticality, "A theory can, once in the pop
science regime, acquire a level of acceptance and momentum that may or may not
be warranted by its actual scientific credibility." And the track record of pop
science enthusiasms is uniformly dismal. Does anyone remember cybernetics or
catastrophe theory? Does anyone know what happened to chaos? It would be
unfortunate if the already worrying faddishness of science were to receive a
presidential seal of approval.
I also have a more specific
worry: that a President Gore would give undue credence to the views of his
favorite pop science heroes and their friends. Occasionally, I have a
nightmarish vision in which the Santa Fe Institute, that temple of "complexity
theory" (whose heavy hitters include Bak, biologist Stuart Kauffman and, yes,
economist Brian
Arthur) actually starts having direct input into major policy decisions.
Now that would be scary.
But I
guess I shouldn't take that nightmare seriously. For one thing, Earth in the
Balance was written a long time ago, and we may suppose that its author has
learned a lot since then. And anyway Gore, if and when he becomes president, is
no more likely to give his personal gurus any real influence than Bill Clinton
would have been to place important policy decisions in the hands of, say, Ira
Magaziner.
Missed our links to 1) on
power laws and 2) an of how the power law applies to city size? Here they are
again.
