Category: Methodology

Neglect of the Important Issues, Is the Opportunity Cost of Pursuing the Cutely Clever

 

The Wall Street Journal summarizes an April 2, 2007 article by Noam Scheiber in The New Republic:

 

A new generation of economists has become so addicted to cleverness that dull but genuinely useful research is under threat.

"Freakonomics," the 2005 best seller that sought to explain the mysteries of everyday life through economics, is only partly to blame, writes Noam Scheiber. The deeper roots lie in a 1980s crisis of faith over economists’ ability to reliably crunch numbers. Influential economist H. Gregg Lewis kicked it off by demonstrating that a host of broad, worthwhile empirical surveys of unions’ impact on wages came to opposite conclusions, mostly thanks to the differing original assumptions by the studies’ authors.

As a result, some economists retrenched, opting to focus on finding "solid answers to modest questions."

 

For the full summary, see:

"Informed Reader; Economics; How ‘Freakonomics’ Quashes Real Debates." The Wall Street Journal (Weds., March 28, 2007):  B11.

 

“A Triumph of Engaged Amateurism”

 

Steven Johnson has a great passage on the contribution of the amateur in The Ghost Map story (see below).

This is a theme that resonates.  In The Long Tail, Chris Anderson makes the case for amateurs in astronomy.  (Is it he, who points out that the root of the word "amateur" is to love?)

Stigler had an important early paper in which he discusses the professionalization of the economics profession.  He praises the results, but what he presents provides some grist for the mill of criticism too.  For example, the exit of the amateurs, reduced the applicability of the work, and turned research more toward internal puzzle-solving, and model-building.

The web is a leveler in science, as suggested in an NBER paper.  Maybe the result will be a resurgence of amateurism, and maybe that won’t be all bad.

 

(p. 202)  But Broad Street should be understood not just as the triumph of rogue science, but also, and just as important, as the triumph of a certain mode of engaged amateurism.  Snow himself was a kind of amateur.  He had no institutional role where cholera was concerned; his interest in the disease was closer to a hobby than a true vocation.  But Whitehead was an amateur par excellence.  He had no medical training, no background in public health.  His only credentials for solving the mystery behind London’s most devastating outbreak of disease were his open and probing mind and his intimate knowledge of the community. 

 

Source:

Johnson, Steven. The Ghost Map: The Story of London’s Most Terrifying Epidemic – and How It Changed Science, Cities, and the Modern World. New York: Riverhead Books, 2006.

 

(Note:  A probably relevant, much praised book, that I have never gotten around to reading, is Martin J.S. Rudwick’s The Great Devonian Controversy:  The Shaping of Scientific Knowledge among Gentlemanly Specialists.)

 

George Stigler on Astrology

 

I remember George Stigler saying (I think in conversation with me, but maybe as an aside in a lecture), that at first he had been inclined to reject a paper for the JPE that empirically tested astrology.  His reason was that, while he liked what the authors were doing, he was not sure that what they were doing, most appropriately belonged in an economics journal.

But when the authors convinced him that they would not be able to publish it anywhere else, he changed his mind and published it.

The episode tells us something about Stigler, and something about scientific method.  About Stigler, the episode provides strong evidence of the importance that Stigler placed on evidence, relative to theory.

On scientific method, the episode can be taken as an illustration of Karl Popper’s distinction between the context of discovery and the context of justification.  There are many sources of hypotheses (the context of discovery).  Famously, Kepler’s inspiration for the elliptical paths of planets, had a somewhat mystical source in the "perfect" solids.  But what makes a theory "scientific" is not its context of discovery, but its context of justification, viz., is the theory subjected to empirical test?

Hypotheses are not ruled out of science ab initio, but by being inconsistent with the evidence.  I agree with this view, which explains why I am a (passive) member of the Society for Scientific Exploration, which is devoted to the empirical testing of politically incorrect theories (such as UFOs, the Shroud of Turin, ESP, the Loch Ness Monster, etc.)

 

The JPE astrology article, accepted by Stigler as editor, was: 

Bennett, James T., and James R. Barth. "Astronomics: A New Approach to Economics?" Journal of Political Economy 81, no. 6 (Nov.-Dec. 1973): 1473-75.

 

A more recent empirical test of an astrological hypothesis is:

Wong, Ka-Fu, and Linda Yung. "Do Dragons Have Better Fate?" Economic Inquiry 43, no. 3 (July 2005): 689-97.

 

For more on Popper’s views of science, consult:

Popper, Karl R. The Logic of Scientific Discovery. New York: Basic Books, 1959.

 

Venturing Into the Mean Streets to Get the Job Done

 

(p. 108)  It is worth pausing for a second to reflect on Snow’s willingness to pursue his investigation this far.  Here we have a man who had reached the very pinnacle of Victorian medical practice—attending on the queen of England with a procedure that he himself had pioneered—who was nonetheless willing to spend every spare moment away from his practice knocking on hundreds of doors in some of London’s most dangerous neighborhoods, seeking out specifically those houses that had been attacked by the most dread disease of the age.  But without that tenacity, without that fearlessness, without that readiness to leave behind the safety of professional success and royal patronage, and venture into the streets, his "grand experiment"—as Snow came to call it—would have gone nowhere.   The miasma theory would have remained unchallenged,

 

Source: 

Johnson, Steven. The Ghost Map: The Story of London’s Most Terrifying Epidemic – and How It Changed Science, Cities, and the Modern World. New York: Riverhead Books, 2006.

 

“Under the Spell of a Theory”

 

Johnson’s wonderful book is part mystery, part history, part philosophy of science, and part musing on political philosophy.  The passage below warms the heart (and stimulates the brain) of the libertarian.  Against great odds, Dr. Snow persisted in presenting ever-more convincing evidence for his correct water-borne theory of cholera.  Meanwhile Chadwick, the main advocate of government public health activities, continued to direct policy on the basis of the mistaken theory that cholera was spread by foul vapors in the air. 

 

(p. 120) Herein lies the dominant irony of the state of British public health in the late 1840s.  Just as Snow was concocting his theory of cholera as a waterborne agent that had to be ingested to do harm, Chadwick was building an elaborate scheme that would deliver the cholera bacteria directly to the mouths of Londoners.  (A modern bioterrorist couldn’t have come up with a more ingenious and far-reaching scheme.)  Sure enough, the cholera returned with a vengeance in 1848-1849, the rising death toll neatly following the Sewer Commission’s cheerful data on the growing supply of waste deposited in the river.  By the end of the outbreak, nearly 15,000 Londoners would be dead.  The first defining act of a modern, centralized public-health authority was to poison an entire urban population.  (There is some precedent to Chadwick’s folly, however.  During the plague years of 1665-1666, popular lore had it that the disease was being spread by dogs and cats.  The Lord Mayor promptly called for a mass extermination of the city’s entire population of pets and strays, which was dutifully carried out by his minions.  Of course, the plague turned out to be (p. 121) transmitted via the rats, whose numbers grew exponentially after the sudden, state-sponsored demise of their only predators.)

Why would the authorities go to such lengths to destroy the Thames?  All the members of these various commissions were fully aware that the waste being flushed into the river was having disastrous effects on the quality of the water.  And they were equally aware that a significant percentage of the population was drinking the water.  Even without a waterborne theory of cholera’s origin, it seems like madness to celebrate the ever-increasing tonnage of human excrement being flushed into the water supply.  And, indeed, it was a kind of madness, the madness that comes from being under the spell of a Theory.  If all smell was disease, if London’s health crisis was entirely attributable to contaminated air, then any effort to rid the houses and streets of miasmatic vapors was worth the cost, even if it meant turning the Thames into a river of sewage.

 

Source: 

Johnson, Steven. The Ghost Map: The Story of London’s Most Terrifying Epidemic – and How It Changed Science, Cities, and the Modern World. New York: Riverhead Books, 2006.

 

New Book on Wiki (Quick) Process

   Source of book image:  http://ec2.images-amazon.com/images/P/1591841380.01._SS500_SCLZZZZZZZ_V37439749_.jpg

 

A new book is out on the wiki ("quick") phenomenon.  Chris Anderson has some stimulating comments on this phenomenon in his The Long Tail.  The Wikinomics book appears to be less profound, but may still be of interest.  (It appears to be a quick-read, management guru-jargon type book.)

The wiki issue that interests me is how wiki collaboration processes might substitute for rigorous editing and peer-review, as a way to get a lot of high-quality information out there fast.  (This is what Anderson claims, and the more I use the Wikipedia, the more plausible I find the claim.)

 

The reference to the book is:

Tapscott, Don, and Anthony D. Williams. Wikinomics: How Mass Collaboration Changes Everything. Portfolio, 2006.

 

Empirical Science at Its Best

   Source of book image:  http://images.barnesandnoble.com/images/11460000/11468284.jpg

 

I have not yet read The Ghost Map, but from the review excerpted below, it sounds like a wonderful book.  One lesson from the book appears to be that much good can come from a careful collection of evidence, and that much harm can come from sticking to a theory in spite of the evidence.  It is also interesting that in this tale, the villain turns out to be the advocate of public works, whose good intentions resulted in much death and suffering. 

 

(p. P8) The sociology of error is a wonderful subject. Some university ought to endow a chair in it — and then make Steven Johnson the first professor. Mr. Johnson last provoked the public with his counterintuitive polemic "Everything Bad Is Good For You," in which he argued that TV and videogames actually improve our cognitive skills. In "The Ghost Map" he tells the story of how for 30 years and more the medical establishment in Victorian London refused to accept what was staring them in the face, namely that cholera was a waterborne disease.

Thousands of Londoners died while doctors and public-health officials stubbornly clung to the view that the plague was an airborne miasma that hung in the foul atmosphere of the slums and was inhaled by the wretched creatures who lived there. Every kind of cure was proposed: opium, linseed oil and hot compresses, smoke, castor oil, brandy — everything but the simple, obvious remedy of rehydration, which reduces the otherwise fatal disease to a bad case of diarrhea.

The fact that the cholera toxin tricks the cells in the lining of the colon into expelling water at a terrifying rate (victims have been known to lose 30% of their body weight in a matter of hours) should surely have alerted someone to the possibility that putting this Niagara back into the body might be worth trying. Only one doctor, Thomas Latta, hit upon the answer, in 1832, just a few months after the first outbreak ever in Britain. His mistake was not to inject enough salty water, and his lone initiative was soon overwhelmed by the brainless babble of the quacks.

Chief among the villains of Mr. Johnson’s unputdownable tale was the man whom we were brought up to revere as the father of public sanitation, Edwin Chadwick. This dour, tactless, unpopular reformer laid the foundations for all the government interventions in public health that we now take for granted. Yet in this story he labored under not one but two illusions that proved catastrophic.

. . .

With the austere teetotaller and vegetarian Dr. Snow and his devoted helper in the Soho slums, the Rev. Henry Whitehead, "The Ghost Map" gains not one but two heroes. Patiently they mapped the patterns of victims and survivors and narrowed down the most likely source of the cholera plague to the Broad Street pump. But even after the pump handle was removed so that Londoners could no longer fill their buckets there and the illness subsided, the miasmatists were not convinced. Snow then tramped the streets of Battersea and Vauxhall to demonstrate that those who had their water from higher up the Thames, above the reach of the tide, remained unharmed, while those who took it from the foul tidewater perished in the hundreds. This was no easy task, since the pattern of water pipes under London’s houses was as tangled as the pattern of Internet service providers are today.

Why did it take so long? Because mapping epidemics was only in its infancy, though Snow’s famous map was not quite the first. Because the questions that Chadwick’s public-health board researched were self-fulfilling, all having to do with the smells and personal habits of the poor and not with the water they drank. The researchers mistook correlation for causation: Nobody died on the high ground of Hampstead, where the air was purer, therefore higher was safer — or so it seemed until a Mrs. Eley, who had retired thither, arranged to receive a jugful of water from her beloved Broad Street pump and got cholera.

But above all Chadwick and his crew were certain of themselves because the stench of the slums was so utterly disgusting and because smell acts so powerfully on our imaginations. Only the most careful and dispassionate investigators were free of the obsession with stench. Henry Mayhew, for example, noted in his "London Labour and the London Poor" (1851) that sewer-hunters, who scavenged deep underground knee-deep in muck, lived to a ripe old age. The Great Stink of 1858, which finally persuaded the government to commission Sir Joseph Bazalgette to lay down the magnificent network of sewers that have lasted to this day, did not kill a single Londoner — yet still Chadwick did not believe.

 

For the full review, see: 

FERDINAND MOUNT.  "BOOKS; Lost in a Time of Cholera; How a doctor’s search solved the mystery of an epidemic in Victorian London."  The Wall Street Journal   (Sat., October 21, 2006):  P8.

(Note: ellipsis added.)

 

The reference to the book is:

Johnson, Steven. The Ghost Map: The Story of London’s Most Terrifying Epidemic – and How It Changed Science, Cities, and the Modern World. New York: Riverhead Books, 2006.  299 pages, $26.95

 

SnowJohn.jpg   Dr. John Snow.  Source of photo:  online version of the WSJ article cited above.

ChadwickEdwin.jpg   Edwin Chadwick.  Source of photo:  online version of the WSJ article cited above.

 

Feynman on Viking Evidence of No Life on Mars

 

Based on the Viking tests, astronomers concluded that there probably was no life on Mars.  Begley (2006) documents the recent research showing that applying the Viking tests to earth, results in the conclusion that there is no life on earth, either.  Once again, Feynman was way ahead of his time:

  

(p. 204)  We like to sit down and talk about how different things could be from what we expected; take the Viking landers on Mars, for example, we were trying to think how many ways there could be life that they couldn’t find with that equipment. 

 

Source: 

Feynman, Richard P. The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman. New York: Perseus Books, 1999.

(Note:  italics in original.)

 

The reference on the Begley article:

Begley, Sharon. "Science Journal; Scientists Revisit Data on Mars with Minds More Open to ‘Life’." The Wall Street Journal  (Fri., October 27, 2006):  B1.

 

“Drawing the Best Minds into a Whirlpool of Mathematical Solipsism”

TroubleWithPhysicsBK.gif   Source of book image:  http://www.houghtonmifflinbooks.com/catalog/titledetail.cfm?titleNumber=689539

 

Physicists rightly feel uneasy about descriptions of the physical world that divide it into discrete clusters of equations and axioms, each cluster explaining one part of existence but not another.  Better would be finding a Theory of Everything capable of conjoining, in a few equations, planet-pulling gravitation and the microcosmic weirdness that goes on in the quantum world of atoms and particles.  Physicists would like to stitch time and space together as well.

Einstein tried and failed.  In recent years, "string theory" has been the favored means of attempting to tie everything together, but it has unraveled into mathematical frippery, positing ever more intricate elaborations extending into anywhere from 10 to 26 dimensions, some arising from themselves, some hidden in ways so baroquely scrolled that you can get a migraine just thinking about thinking about them.  Little wonder that, as an experimental science, string theory seems to have nowhere to go.

That is the problem that Lee Smolin identifies in "The Trouble With Physics."  He laments a kind of sociological imperative drawing the best minds into a whirlpool of mathematical solipsism.

 

For the full review, see:

RUSSELL SEITZ.  "BOOKS; Untangling the Knots in String Theory."  The Wall Street Journal  (Sat., December 2, 2006):  P9.

 

The reference to the book under review, is: 

Lee Smolin.  The Trouble With Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next.  Houghton Mifflin, 2006.  (392 pages, $26)

 

Publishing Pretty Papers Full of Clever Mathematical Tricks

  Source of book image:  http://images.amazon.com/images/P/0738203491.01.LZZZZZZZ.jpg

 

In his elegant and thoughtful foreward, physicist, futurist, and guru Freeman Dyson writes:

(p. viii)  Before I met Feynman, I had published a number of mathematical papers, full of clever tricks but totally lacking in im-(p. ix)portance.  When I met Feynman, I knew at once that I had entered another world.  He was not interested in publishing pretty papers.  He was struggling, more intensely than I had ever seen anyone struggle, to understand the workings of nature by rebuilding physics from the bottom up.   

 

The reference to the book, is:

Feynman, Richard P. The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman. New York: Perseus Books, 1999.

Schumpeter’s “Sarcastic Remark” on Mathematics in Economics

Erich Schneider had been a student of Schumpeter’s at the University of Bonn in the late 1920s.  The following sentences are from his lectures on Schumpeter that he published in German in 1970, and that were were translated into English by W.E. Kuhn and published in that form in 1975.

(p. 41) When, after many years of separation, I saw Schumpeter again at Harvard in the fall of 1949 and heard his lectures on economic theory–which he gave at 2 p.m., as in Bonn–I found him to be exactly the same man as before. On that afternoon he talked about the nature of dynamic analysis and about the role of difference equations in the framework of such an analysis.

To the above passage, Schneider adds footnote 3:

(p. 59) He dropped the sarcastic remark: "There are economists who do not know what a difference equation is; but there are also those who know nothing else."

Schneider, Erich.  Joseph A. Schumpeter:  Leben Und Werk Eines Grossen Sozialokonomen (Life and Work of a Great Social Scientist). Lincoln, Neb.:  University of Nebraska–Lincoln Bureau of Business Research, 1975.