|
|
||
| Algorithms Probing the vice president's thought processes. By Paul Krugman 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. |
| 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 here.)
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 here.) |
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:
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) more information on power laws and 2) an example of how the power law applies to city size? Here they are again.
Illustrations by Robert Neubecker. |
|
||||||||||||||||||||||||
|
||||||||||||||||||||||||
|
||||||||||||||||||||||||
Links
