Friday, August 31, 2007

This is important...

I'm totally bogged down in an article in quantum non-locality, which is one of my most long-standing pet interests. I'll say more next week, after finishing the article, but I'm beginning to believe that social dynamics have actually had quite a lot to do with this area of physics over the past 50 years. For many years, in effect, people were unable to get jobs at good institutions if they wished to work in unorthodox areas, especially if they questioned the prevailing orthodoxy on the interpretation of quantum theory.

Scientists are people too, and all the usual dynamics and pressures of fashion and group influence work there too. Anyway, in the past few days, I learned of some new work that, if it turns out to be free of holes and as important as it seems to me, may be the most profound development in quantum theory (and therefore basic physics) in maybe 40 years. In essence, it suggests that the widespread belief that quantum theory demands a break with ordinary thinking and with a belief in a reality that exists separate from our observation of it may be very much incorrect.

But more on that later. Here's a link to something much more down-to-earth, and important, in a very practical sense. Our government, it is clear, will get away with whatever we let them get away with.

Sunday, August 26, 2007

Who's the real enemy?

In an Op-Ed last weekend, the New York Times' Thomas Friedman asked some curious questions, questions with answers that I think ought to be all-too-obvious. He wrote:

One thing that has always baffled me about the Bush team’s war effort in Iraq and against Al Qaeda is this: How could an administration that was so good at Swift-boating its political opponents at home be so inept at Swift-boating its geopolitical opponents abroad?

How could the Bush team Swift-boat John Kerry and Max Cleland — authentic Vietnam war heroes, whom the White House turned into surrendering pacifists in the war on terror — but never manage to Swift-boat Osama bin Laden, a genocidal monster, who today is still regarded in many quarters as the vanguard of anti-American “resistance.”


Is it really too much to comprehend that perhaps, in a White House in which "everything is driven by the political arm," the likes of John Kerry and Max Cleland were seen as greater threats than Osama bin Laden, or any other terrorist for that matter, and so smearing domestic opponents took (and still probably takes) priority over anything having to do with the "reality based" world?

I don't find anything puzzling here at all. This administration invented the "War on Terror," and induced every major news organization to go along with the phrase, making it seem almost like an element of objective reality, rather than the very effective demonstration of framing that it is. Terrorism may be real, but the "War on Terror" is a psychological tool of US politics.

I haven't seen any evidence to dissuade me from the belief that this administration is far more interested in appearing to face up to the threat, than in actually doing so.

Property values NEVER go down...

Apparently some people, even many people, really believe this. Indeed, a friend of mine said as much to me a couple years ago. "House prices always goes up." He meant even more than that, believing that house prices always rise faster than inflation. Which may be true if you take only the past ten years as evidence. Go a little further back, of course, and you see that house prices flop up and down just like anything else, sometimes very rapidly, often driven by collective waves of behavior that look decidedly like the consequence of imitation. Stalwart economists may still harbor doubts, but property markets herd just like equity markets; only the time scales are different.

House prices are now set to fall, as the New York Times reports. That's not really so interesting; more interesting is the human dynamics behind the story. "Many government officials and housing-industry executives,"the article reports, "had said that a nationwide decline would never happen." On what possible grounds? If you suspect some conflicts of interest, I think you wouldn't be too far wrong.

As just one example, the article quotes Ben Bernancke:

In 2005, Ben S. Bernanke, then an adviser to President Bush and now the Fed chairman, said “strong fundamentals” were the main force behind the rise in prices. “We’ve never had a decline in housing prices on a nationwide basis,” he added.

That, pure and simple, was a form of cheerleading.

We're not so good at predicting the future when the past is given to us as statistics about "fundamentals," or sold to us in glowing terms by those with vested interests in keeping the bubble going. But one thing people are really good at is detecting patterns. We can recognize a person we know, even someone we haven't seen in a couple years, after a glimpse of the back of their head at 50 yards.

For a bit of fun, check out this video that puts you on a rollercoaster ride through housing prices, adjusted for inflation, over the past 120 years. After a century of riding, I think you'll have a good feel for the typical ups and downs of the market; and, I suspect, an accurate expectation of what might come next.

Thursday, August 23, 2007

Fickle preferences...

I still haven't yet finished that old paper by Gary Becker, but I hope to get back to it soon, and see whether or not I treated his ideas fairly in The Social Atom. In the paper, he's trying to argue that economists can make much weaker assumptions about the rationality of people, and still derive some of the key theorems of economic theory. I have my doubts, but I'm not quite ready yet to lay out why in detail.

One of the problems, I suspect, may hinge on the notion of fixed preferences. Economists tend to assume that people have fixed preferences -- say, for deciding between apples and oranges. If those preferences are indeed fixed and independent of any situation, then it's easy to understand if you see lots of people eating apples and few eating oranges; what you see in the group, in the aggregate, is merely the summation of the preferences of the individuals. There's a technique that theorists use to formalize this intuition, called the Representative Agent. If you see that 80% of the people are eating apples, then you can infer that 80% prefer apples to oranges. (Effectively, you could also treat the response of the crowd as if it was the response of a single "representative agent," who likes to mix apples and oranges in a four to one ratio; in mathematical theories, this is done for convenience.)

Trouble arises, however, if one assumes that this representative agent trick can always be carried through. And it clearly cannot if people interact (which they do!), and if what one person prefers depends on what others prefer, or on what they actually choose to do (which it often does!). In an extreme case, for example, most people might (on their own) prefer apples to oranges, but also have a strong preference to eat what they see most other people eating. If one person starts out by eating an orange, and a second follows suit, so may all the rest, leading to an outcome that doesn't reflect the "innate" preferences of the group, but the way the dynamics of influence can easily twist peoples' preferences away from their independent values.

Economists have long tried to get by with this representative agent trick, as it greatly simplifies the task of going from some knowledge of what individuals want to how a group will behave. Unfortunately, it is a very serious mistake, as it effectively cuts the interactions of people out of the loop. And interactions count.

As one intriguing example, some Chilean and Columbian economists, working at the Santa Fe Institute, have recently been studying the way people manage limited resources. In experiments, they had people "extract resources" from a mythical reservoir (think grasslands, minerals, fresh water, etc). Each person could choose how much to take. The more they take, the more they get, in general, except there's also a cost -- if everyone takes a lot, the resources gets depleted and then everyone suffers. The study is fairly involved, and I won't get into the details, but one fascinating outcome is that the fact that peoples' preferences can be influenced by what others do can have a great effect.

Many individuals feel guilty if they take too much (more than an accepted social norm). In some of the experiments, they found that this guilt (particularly when backed up by the small threat of a fine for taking too much), led to a stable situation in which the people extracted resources in a healthy, sustainable way. However, many people only feel guilt in overextracting as long as others aren't overextracting too; if many others do begin to take out too much, many individuals lose their guilty feelings and will join in. As a result, even under the same conditions, the group's behavior can end up in two different states, pushed into one or another by some initial accident -- not unlike the example of the apples and oranges.

I think this emphasizes the major theme of The Social Atom pretty well; people cann't be understood in isolation, and then summed together, to get social reality. It emerges inherently from the collective patterns born of their interactions. Not really an earth-shaking thought, but one that many scientists have tried to suppress for many years.

Our hapless media...

The ever-active Glenn Greenwald cites yet another example of the sad failing of our media's "finest" to render poltical events in anything like a "fair and balanced" manner. As I tentatively suggested last week, our media figures could do a great service to our democracy -- not to mention to the standing of journalism itself --if they tried a bit harder to act as intelligent and independent minds in their own right, and to peer behind the themes and images given them by political figures and operatives, so as to help Americans know and understand the world, insofar as that might be possible. The Washington Post's Anne Kornblut clearly hasn't yet mastered the requisite skills, relatively simple though they may be. An excerpt from Tuesday night's Hardball:

KORNBLUT: It remains, especially in Democratic crowds, the number-one issue. There is no applause line that gets a bigger response when you're out with Senator Hillary Clinton, Barack Obama, John Edwards, than when they say the first thing I'm going to do is I'm going to start ending this war in Iraq.

Republican crowds are a little different. They still want to be supporting the troops.


Notice the logic, or rather the lack thereof. She might as well have said "Republicans are a little different, they still hold America in high esteem and do not want to dishonor the dead." Or, "Democrats want to start ending this war, but Republicans are a little different - they love their children and see hard work and responsibility as a good thing, not something to be ashamed of." Etc.

This is indeed a very crafty way to use, or misuse, language. "Republican crowds are a little different. They still want ..." sets us up to take whatever comes next as roughly the opposite of what Democrats want. The speaker then has free reign to say anything, knowing that the association is implicitly made.

I find it very hard to believe this is mere incompetence. Okay, speaking on the fly on television isn't easy, but a "political analyst" with any skill and experience ought to be able to avoid a juvenile error like this. It ought to be almost automatic; second nature. I cannot imagine myself, in a context more close to my own knowledge base, saying something like "Classical physics attibutes a precise position and velocity to a particle, such as an electron. Quantum physics is a little different. It views the world as something that can be explained, often in terms of elegant mathematical theory."

Indeed, I found it quite difficult even to construct that example, as my brain strongly demanded that I follow "It views..." with some statement about whether quantum theory attributes precise positions and velocities to particles. But someone reading could easily come away thinking that "classical physics" doesn't see the world as something that can be explained.

Alas, however, this kind of mushy and slippery thinking and speaking routinely passes as "analysis." Why even bother educating journalists? Greenwald summarized the point quite clearly, referring to the potentially useful role of "analysts":

One of the principal functions of political reporters ought to be to dissect and dispense with misleading political sloganeering, but instead, they fulfill the opposite function: they are the most enthusiastic and effective disseminators of these cliches.

...Instead, this sort of cheap sloganeering entirely engulfs the analysis itself and becomes the only way many political journalists can think and talk about political issues.

Tuesday, August 21, 2007

Rational or irrational?

A few weeks ago, Dr James B. Burnham of the Donahue Graduate School of Business at Duquesne University sent me a polite email chiding me for my discussion, in The Social Atom, of the work of economist Gary Becker. Becker is famous for his association with the so-called Rational Choice school of economic thinking, which tries to model a great deal of human behaviour -- including things like crime, individuals' choices to have children and so on -- in terms of people making fully rational choices. Becker's Nobel Prize Lecture from 1992 offers a nice synopsis of the principle ideas and some of their applications.

I portrayed Becker as being rather strongly committed to the rationalistic viewpoint, and Burnham quite rightly points out that I overlooked a classic work of Becker's, Irrational Behavior and Economic Theory, published in the Journal of Political Economy, February 1962. In the paper, it seems, Becker tried to establish some of the central "theorems" of classical economics without insisting on full individual rationality. Dr. Burnham was also kind enough to send me a copy of the paper, and I'm in the process of reading it. Hopefully I'll be able to comment tomorrow on just how fairly or unfairly I treated him.

But I came across something today, not quite as old as the overlooked Becker paper, that I suspect may shed some light on the question of whether people are rational or not, and when economic rationality can be assumed without fear of getting things rather completely wrong. The paper in question is a short review from last year by economists Ernst Fehr and Colin Camerer, looking at the question of how the collective logic of a situation can strongly influence human behaviour -- sometimes even making rational people act "irrationally," with important consequences.

Contrast the following two situations:

1. Suppose you'd like to try to win some money by playing the University of Iowa Presidential Election Market for the 2008 election. The idea is that you can buy a contract that will pay off if, when the election takes place, the numbers turn out a certain way. The contract you buy should reflect what you think is really going to happen, and accuracy will make it pay out more. Suppose you're an extremely well informed political analyst, more knowledgeable and with access to more information than just about anyone. Then you should act rationally, making your best guess. If everyone else playing the market goes half mad and starts buying futures for some completely implausible candidate, so be it; you'd have no incentive to follow. The more crazies out there, the more your cool wisdom will pay off.

2. Suppose instead that you decide to play the stock market. Again, being a bright and well informed individual, you scour the financial pages and identify one stock that you're sure is undervalued. Maybe it's IBM. You know they're in healthy condition, with diversified interests and good leadership, even though many irrational investors, lured by sexier stocks in smaller companies, have ignored IBM and pushed its value down unreasonably. So what do you do? Apparently, it seems, you could follow a similar strategy to the example above. Trust your own superior knowledge, buy up lots of IBM stock, and then sit back and wait for the price to return to it proper, reasonable value. Then you can sell it for a killing, making easy money.

The problem, as Fehr and Camerer point out, is that these two situations, though superficially similar, are actually totally different.

In the first case, other people being irrational gives you no incentive to follow along. The collective logic -- and the fact the election will take place on a specific date, at which point all contracts will be settled -- means that rational strategies work best. But in the second case, there's no guarantee. You may in all sound wisdom buy up the undervalued IBM stock, and then find over coming weeks and months that the irrational mob only acts to devalue it more. The herd may push its price down to ridiculous levels and leave it there for years; keeping your money in the dumps while it could have been earning interest elsewhere. In the latter situation, the rational can easily be forced to follow along with the irrational herd.

Fehr and Camerer argue that these examples illustrate a general pattern:

Individuals who violate the assumptions of economics may create powerful economic incentives for Economic Man to change his behavior...


This is indeed one of the major shortomings of any theory that assumes rational behavior; rational action, in a sense, is often just not possible, and people have to rely on other means for making decisions. Other people acting irrationally -- stampeding across a bridge, for example -- may quickly make stampeding across a bridge the only wise thing to do. What happens in the aggregate of many people is often in no way simply a summation of what they would have desired a few moments ago.

What, if anything, this might have to do with the attempts of Gary Becker to relax the assumptions behind theorems of classical economics, I don't know. I suspect there may be some holes in his reasoning, and they may center on whether the actions of individuals are independent, or whether what one person does has consequences for what others do. But we'll see...

Monday, August 20, 2007

Rove's legacy

I couldn't agree more with this assessment of the legacy of Karl Rove by Juan Cole. If there was ever a time when the rift between the left and right in the US could have been temporarily healed, and our collective energy harnessed for genuine improvement of our nation and the world, it was in the immediate aftermath of 9/11. Instead, Rove casually sacrificed that historic opportunity on the alter of momentary political gain. As Cole puts it,

... his most tragic legacy lay in taking something that happened to all Americans, the murderous attacks of Sept. 11, and attempting to turn those calamities into a stick with which to beat his Democratic opponents. In so doing, he desecrated the nearly 3,000 dead for petty factional gains, and wrought enormous injustices on genuine war heroes such as Max Cleland, George McGovern and John Kerry. Long after his permanent Republican majority is forgotten, Rove will be remembered for using his rhetorical gifts to divide instead of unite.


Rove's tactics were deplorable, damaging and, in my view at least, thoroughly un-American. One thing you cannot call them, however, is novel. He's clearly a fine student of history, and the historical lessons of dividing a people against themselves, especially in times of apparent danger when they are most easily manipulated. As Ian Welsh pointed out a while ago, Rove's insights have been used before, even more effectively, and with far greater consequences...

...voice or no voice, the people can always be brought to the bidding of the leaders. That is easy. All you have to do is tell them they are being attacked and denounce the pacifists for lack of patriotism and exposing the country to danger. It works the same way in any country."- Herman Goering

Friday, August 17, 2007

Torturing light...

This post really has little to do with The Social Atom, but I've had no time to blog anything today, as I've been occupied with a last-minute article on some recent physics research. Physicists are getting ever closer to building material systems that will coax photons, the quantum particles of light, to interact with one another. Ordinarily, that never happens; flashlight beams, for example, just pass through one another. But it turns out that with some really tricky quantum optics, it should be possible to effect (which quantum theory says is possible).

You may ask -- why even try? I'll get to that.

The bizarre things researchers are developing to achieve this illustrate the way science leads in directions that no one could possibly imagine beforehand; truth really is stranger than fiction. One prominent proposal, for example, involves lasers illuminating thin films of diamond, within which specially-chosen atoms have been embedded amidst a precise pattern of tiny, drilled microholes. Without getting into the details, the quantum physics of this weird system leads is an array of cavities which can trap single photons. With the cavities arranged in precise geometric arrays, the photons in neighboring cavities will interact fairly strongly with one another, and so what you get is a system akin to a collection of interacting photons. It hasn't been done yet in the lab, but the principles are so well understood that it almost certainly will be done in a few years.

Now back to the why. Why do this? There are a couple of reasons, besides it's being just good fun and a challenge leading to new physics (which I think is probably the most important reason, by the way). First, there's good reason for expecting that interacting photons would be exceedingly useful for doing quantum information processing; i.e. as parts of quantum computers. But well before that, physicists also expect they'll be able to use these photon systems as "quantum simulators" to do virtual experiments mimicking just about any kind of particle system you like.

When we think of simulation we ordinarily think of simulation by computer; but if you think about it, simulation really has nothing to do with computers. It really means using something that is simpler or faster or easier to use to study the behavior of something else, under conditions when you have confidence that the two things should work similarly, so you can learn about the one from the other. Theorists have shown that interacting photon systems could be tuned to dial up just about any physics you like -- any details about the interactions between particles -- and so could be used to do virtual experiments for all kinds of hypotheticl materials, even ones that don't exist.

Curiously, I just came across a review in Nature, written by my former colleague Phil Ball, of two new books on simulation in the social sciences. As the review notes,

..these two books are part of an important trend in the social sciences. Both argue for the value of agent-based modelling (ABM) in social science. This approach involves "growing societies from the bottom up", as Epstein has put it, rather than devising analytically airtight theorems from first principles that are tractable but transparently wrong in what they assume and imply about human behaviour.

The aim of ABM is to study whether the macroscopic patterns or regularities that we observe in society, such as price equilibria or the appearance of behavioural norms, can be generated from decentralized, local interactions between collections of agents.... Agent-based models may not describe reality, but they can show how interaction and nonlinearity produce social outcomes that could not be predicted simply by inspecting the behavioural rules.


Of course, all this is simulation, in this case using computers, which help us go beyond what our human brains can foresee in situations in which many factors begin working off one another. For the moment, quantum simulators are tuned specifically to atomic systems, and I'm not sure how far they might be generalized in the future. I can't imagine that quantum simulators in thin diamond films will ever be used to shed light on important social questions, by modeling social interactions, but then, who knows -- and why not?

Thursday, August 16, 2007

The higher (or lower?) language

It's quite clear by now that much of our national discourse on topics ranging from gay marriage to Iraq to global warming takes place not in terms of facts but in the more powerful language of emotional associations, in terms of ideology. Framing counts for more than facts (as Republicans seem to understand better than Democrats, for some reason), in part because of the power of modern media to spread simple messages and sound bites far and wide, and their inability or unwillingness to act as honest interpreters of framing strategy.

In a New York Times essay that I never got around to writing, I had intended to argue that the proper role for the media in today's world ought to be as "censors" of a sort, or exposers of framing. For example, rather than merely providing a forum and promulgating Republican claims that war opponents "hate America" or are "helping the enemy," the press ought to provide independent assessment and comment on how such attacks aim to frame the war debate in a way favorable to Republicans. And vice-versa for Democrats. When Hillary Clinton attacks Obama for saying nuclear weapons should be off the table in pursuing terrorists, the press shouldn't merely repeat her words that "Presidents since the Cold War have used nuclear deterrents to keep the peace, and I don't believe any president should make blanket statements with the regard to use or non-use." Comment ought to focus on the obvious Clinton strategy of trying to paint Obama as being "unpresidential" and inexperienced. Reporting (sadly quite a lot of it) that quotes political figures without commenting on the frames they're attempting to establish really is mere stenography.

If you have a spare hour, I highly recommend this podcast of an entertaining and deeply informative lecture at Xerox PARC by Geoffrey Nunberg of the University of California, Berkeley. Entitled The Paradox of Political Language, this is the abstract:

There's a paradox in modern attitudes about political language. Left and right may disagree as to which expressions count as deceptive packaging and which are merely effective branding, but both sides acknowledge that the American public is particularly susceptible to linguistic manipulation. Yet it's also fair to say that there has never been an age that was so wary of the mischief that language can work or so alert to the dangers of political euphemism and indirection. How did we come to this point? Are political and public figures really more mendacious than they used to be, or does it reflect a changing media role or an increasingly polarized political climate? Why is widespread sophistication no impediment to the misleading use of language, and why do many of the most successful linguistic maneuvers pass our radar undetected?


Actually, I hadn't really intended to post on this subject, but it came to mind this morning when reading a spirited opinion piece by Nicolas Kristof in the New York Times. If you don't think framing and metaphor can help alter the terms of a debate, read this:

If we learned that Al Qaeda was secretly developing a new terrorist technique that could disrupt water supplies around the globe, force tens of millions from their homes and potentially endanger our entire planet, we would be aroused into a frenzy and deploy every possible asset to neutralize the threat.

Yet that is precisely the threat that we’re creating ourselves, with our greenhouse gases. While there is still much uncertainty about the severity of the consequences, a series of new studies indicate that we’re cooking our favorite planet more quickly than experts had expected...


That's effective framing.

Wednesday, August 15, 2007

Sex by numbers

Basic biology in many species pushes males and females toward different reproductive strategies, with males in some cases tending to seek as many partners as possible, and females -- because they invest so much more physically in producing offspring, and could even die in the process -- seeking one stable partner. The folklore in humans is that men tend to be more promiscuous than women, and its the biology that makes them do it.

In surveys, sure enough, this is what you find -- men report having, on average, more sexual partners than women. In one fairly recent study, sociologist Frederick Liljeros and colleagues found this pattern clearly among men and women in Sweden (they also found that the network of sexual contacts is highly skewed, with a few men and women having far more partners than most others). But this light article in the New York Times raises a fair question. Excluding homosexual contacts, the total number of times that females have sex has to be identical to the number of times males have sex; hence, the average number of sexual contacts for men and women has to be equal, simply by mathematics.

Liljeros et al. noted this in the paper I mentioned, and suggested that it might have something to do with males over-reporting their numbers, "bragging" about their impressive success. But I suspect there is probably also significant female under-reporting, especially as traditional norms in most societies take a dim view of female promiscuity. (One point the article doesn't explore is whether men and woman might interpret the word "sex" differently, leading to some encounters being viewed as sex by one partner, and non-sex by the other...but I'm guessing careful studies control for that by using some strict and unambiguous definition).

This systematic deviation of what people report from the underlying reality probably tells us something about mating strategies themselves; perhaps, for example, that females have a greater incentive than males to keep their promiscuity hidden. I came across an interesting essay on the topic, not by a biologist, oddly enough, but by Eric Raymond, a fellow linked in some deep way to the Open Source movement. No matter, it's a nice essay anyway, and informative. As Raymond argues:

Actual paternity/maternity-marker studies in urban populations done under guarantees that one's spouse and others won't see the results have found that the percentage of adulterous children born to married women with ready access to other men can be startlingly high, often in the 25% to 45% range. In most cases, the father has no idea and the mother, in the nature of things, was unsure before the assay.

These statistics cry out for explanation -- and it turns out women do have an evolutionary incentive to screw around. The light began to dawn during studies of chimpanzee populations. Female chimps who spurn low-status bachelor males from their own band are much more willing to have sex with low-status bachelor males from other bands.

That turned out to be the critical clue. There may be other incentives we don't understand, but it turns out that women genetically "want" both to keep an alpha male faithful and to capture maximum genetic variation in their offspring. Maximum genetic variation increases the chance that some offspring will survive the vicissitudes of rapidly-changing environmental stresses, of which a notably important one is co-evolving parasites and pathogens.


So maybe neither sex is the "more" promiscuous.

Tuesday, August 14, 2007

Only in America...

...could a mainstream newspaper mix up the views of scholars from Princeton, the University of Chicago, and a number of other real institutions -- institutions with a devotion to scientific standards -- with those of supposed "scholars" from the likes of the American Enterprise Institute. The Washington Post managed that in this article on research showing how Americans, once the tallest people in the world, have now fallen to being ranked ninth. The article quoted experts from various fields, and from the following places:

John Komlos, University of Munich
Robert Fogel, University of Chicago
Richard Steckel, Ohio State University
Barry Bogin, Loughborough University, UK
Tom Miller, American Enterprise Institute
Angus Deaton, Princeton University

Why on Earth would someone from the AEI appear on such a list? Well, it's fairly easy to see if you look at the content of the article. What are some of the possible causes of our collective loss of stature? Komlos himself suggests a lack of quality health care for children during the crucial stages of early development:

"We conjecture that perhaps the western and northern European welfare states, with their universal socioeconomic safety nets, are able to provide a higher biological standard of living to their children and youth than the more free-market-oriented U.S. economy," Komlos wrote in one of his latest papers, published in June in the journal Social Science Quarterly.


Perhaps, one might also conjecture, our not-so-healthy eating habits have something to do with it:

Komlos and others noted that the contemporary American diet, while plentiful, has become less nutritious in some ways, especially in recent years, which has helped fuel the obesity epidemic, particularly among children. So while Americans are no longer the tallest, they are among the widest.

"The culture of food here is different than other countries," said Richard H. Steckel of Ohio State University. "Children tend to watch more television and snack and eat fast food. When they do this, the fuel they are consuming is not the optimal blend."

The United States also lags far behind other countries in a host of important markers for childhood well-being. Rates of infant mortality, low-birth-weight babies and childhood poverty remain well higher than those in many European countries, and rates of childhood vaccination are much lower.


From the point of view of basic biology, all these factors would be expected to have a clear influence. Indeed, the one biologist quoted says as much:

"What we're finding out is it's the basic quality of the environment in which people grow up that's crucial, and it takes several generations to overcome poorer environments in the past," said Barry Bogin, a biological anthropologist at Loughborough University in Britain.


Ah, but now, with some many authorities suggesting we have a real problem with nutrition, and with health care, which might well suggest we do something about it, the writer must have felt some pressure to find someone, somewhere, to say that we shouldn't do anything because that would be jumping to conclusions. Where could you find such a "scholar"? Well, right over at the handy American Enterprise Institute:

But others are skeptical, noting that aside from the Dutch, the differences between Americans and other countries are small. There are also wide variations within every country, and it's difficult to compare a large heterogeneous country such as the United States with small homogeneous countries such as the Netherlands, they say. The effect of immigration can last generations.

"Some of these other countries probably have better family structure in terms of children growing up in two-parent households, for example," said Tom Miller, who studies health-care policy issues at the American Enterprise Institute. "It's a crude and simplistic approach to just say, 'Let's pour some more money into the health-care system.' "


The illogic of this discussion and quotation is rather breathtaking. First, just because the differences in size are small doesn't mean they're not significant. Second, the fact that there are variations within countries doesn't mean we cannot compare their averages, and draw meaningful conclusions. Third, no one in the article so far had suggested that we "pour some money" into health care; only that a lack of quality health care quite possibly has something to do with the trend.

I can't really understand how any reporter at a major newspaper could include such comment from a source with obvious political and ideological motivations, but then I must not have any idea how major newspapers work.

Then again, maybe there's a pattern at the Washington Post. As The Agonist pointed out yesterday, in their wrap-up of the Iowa Straw Poll, the Post managed a curious listing of the Republican finishers, indicating who was 1st, 2nd, 3rd, 4th, and 6th -- somehow just skipping over number 5 without mention. Who was that? Oh, it happened to be the controversial and, for Republicans, rather inconvenient Ron Paul.

It's hard not to agree with Ian Welsh:

It appears that even pretending to do journalism, or making gestures at being unbiased is too much for the Post these days.

The chemistry of crime?

I wrote a little in The Social Atom on the topic of crime and its dynamics. An old idea in the field holds that crime has economic origins; that it arises out of the cost-benefit analysis of the criminal, who decides, given his or her situation, that the benefits of breaking the law outweigh the risks. Read economist Gary Becker's 1992 Nobel Prize Lecture, and you see that this influential way of thinking about crime -- thrust upon him by a minor experience in his own life -- stimulated his efforts to apply "rational choice" theory more broadly:

I began to think about crime in the 1960s after driving to Columbia University for an oral examination of a student in economic theory. I was late and had to decide quickly whether to put the car in a parking lot or risk getting a ticket for parking illegally on the street. I calculated the likelihood of getting a ticket, the size of the penalty, and the cost of putting the car in a lot. I decided it paid to take the risk and park on the street. (I did not get a ticket.)

As I walked the few blocks to the examination room, it occurred to me that the city authorities had probably gone through a similar analysis. The frequency of their inspection of parked vehicles and the size of the penalty imposed on violators should depend on their estimates of the type of calculations potential violators like me would make.


In this way of seeing crime as a rational response to economic conditions, Becker was reacting to the earlier view which saw crime as the outcome of mental deficiencies and aberrations. Neither of these perspectives, at least as naively interpreted, has proven very successful in accounting for the data on crime. In an important study a few years ago, economists Edward Glaeser, Bruce Sacerdote and Jose Scheinkman looked at how crime rates fluctuate from place to place, within nations or within individual cities, and found variations far too strong to be attributed to economic conditions alone. As they pointed out,

...even casual empiricism suggests that differences in observable local area characteristics can account for little of the variation in crime rates over space. ...The 51st precinct of New York City has 0.046 crimes per capita while the wealthier 49th precinct has 0.116 crimes per capita. ...More rigorously, we generally find that less than 30 percent of the variation of cross-city or cross-precint crime rates can be explained by local area attributes.


Rather, they suggested that "social interactions" of some kind must be at work; for example, the way a culture of crime in a particular community can make it more likely for young people to become criminals, so that criminal behavior propagates on its own. One person's decision to commit a crime makes it more likely that their friend or brother will commit a crime. There is, no doubt, a strong element of truth in this, but I just learned about another fascinating perspective on crime, with perhaps more specific applicability, which sees it dynamics as a process quite closely akin to physics or chemistry -- it takes a step back toward Becker's view, seeing crime as a somewhat mechanical and unsurprising outcome under the right conditions, yet without being quite so insistent on the "rationality" of the perpetrator.

I've been listening to a recent lecture (podcast and pdf slides available here) by criminologist Marcus Felson of Rutgers University. Nearly thirty years ago, as a young professor, he introduced a way of looking at crime called "routine activity" theory. In his lecture, he says, the idea...

... was considered very strange at the time, and may be still. We argued that to study crime you needn't worry so much about offenders; that indeed an illegal act involves an offender and a target and the absence of a guardian against the crime. There's a physical convergence that has to occur, and if the physical convergence does not occur, then a normal crime does not occur. As a result, the targets for crime may be more important than the offenders, and the guardians for crime, the people who would stop a crime, may be more important than offenders.

This makes crime much more a physical phenomenon.


In Felson's view of crime, the important factors are offenders, targets and guardians, and the process is largely mathematical, aking to a kind of basic social chemistry. When offenders come into contact with targets, crime has a chance of happening, unless a guardian happens to be there (and this needn't be a police figure, but could be just any ordinary person who happens to be watching a car, house, etc.) So understanding crime, and how to prevent it, means looking at all the details that influence how and when offenders and targets make contact in the absence of guardians. Often, this comes down to relatively simple details of the exposure of targets and the flows of people. For example, of two identical houses, one on a main street and another on a smaller street requiring two further turns to be reached, the latter turns out to be much less likely to be burgled, simply because its harder to reach (Patricia Brantingham mentioned this example in her lecture from the same conference.)

I'm on a bit of a push to explore this area over the next week or so, so I'll write more in coming days on the chemistry of crime, and how it is being increasingly applied to make a real difference. A relatively new idea called "situational crime prevention" takes this chemistry view seriously, and tries to prevent crime by taking away the conditions under which the necessary "reactions" can take place. Situational preention, as Felson says in his lecture,

...focuses on the very local conditions or very direct conditions that physically make it more difficult to carry out a crime. And increasingly we've discovered ... that crime prevented here does not simply crop up elsewhere...that [crime] displacement is not nearly the problem it was once thought to be... and that crime really can be prevented substantially by rather direct methods ...


From what I know so far, this does seem to fit the them of thinking more about patterns than people. The social world is a physical process with human flows and reactions between people of various sorts, and we can make a difference by thinking specifically in those terms.

Friday, August 10, 2007

The Bangladeshi Queen

An amusing anecdote to finish off this short Robert Putnam series. From an essay by John Lloyd in the Financial Times:

When Robert Putnam published “Bowling Alone” six years ago, the book brought the Harvard professor such fame he was invited to speak at Camp David, 10 Downing Street - and Buckingham Palace.

When he arrived to meet the Queen, he found Her Majesty absent but her top courtiers anxious to hear his advice for a multi-racial Britain. Noting that great royal houses had often used marriage to forge important political alliances, he advised them to “go look for a nice Bangladeshi girl for one of the royal princes”.

There was dead silence. “No-one spoke,” he said. “Later, the man from Downing Street who had taken me there said, ‘Bob, maybe that wasn’t quite what they wanted to hear.’ ”

Thursday, August 9, 2007

Diversity II

Just a few more comments on ethnic diversity and social cohesion. Robert Putnam's new study shows that more diversity tends to be correlated with lower levels of trust in a community, at least in the U.S. This is an important finding, and shows that diversity does come with a cost at least in the short run. Putnam shows that diversity in the long run has lots of benefits, even economic benefits, but in the short term, trust languishes as people learn to adapt and navigate a new social world .

One really interesting point that he also dwells on is the difficulty of defining diversity, because of the inherent malleability of group boundaries. How we divide people today into different ethnic groups isn't how we'll group them tomorrow; we're constantly changing which markers (skin color, style of dress, religion) seem more or less important. As a nice example, he cites his personal experience of the waning importance of religious boundaries:

I grew up in a small town in the Midwest in the 1950s. Of the 150 students in my senior class, I knew the religion of virtually every one. Even now, when I have long forgotten their names, I can generally remember who was a Catholic, who was a Methodist and so on. Nor was that some personal quirk of mine, because in fact most of my classmates knew everyone else’s religion. My own children, who went to high school in the 1980s, knew the religion of hardly any of their classmates. ... over those thirty years religious endogamy (the practice of marrying only within one’s faith) has largely faded in America, at least among mainline Protestants and Catholics and Jews. In the 1950s, for the most important aspect of any adolescent’s life – mating – it was essential to keep track of one’s peers’ religious affiliations. By the 1980s, religion was hardly more important than left- or right-handedness to romance.


Even skin color, which seems to be so deeply ingrained in our minds as a salient social marker, isn't actually hard-wired in any sense. I've written earlier about the fascinating experiments of Robert Kurzban, John Tooby, and Leda Cosmides showing that racial awareness can be erased. What we're really good at is detecting group affiliations among people, and using such affiliations as tools to navigate the social world. We'll latch onto any marker that works as a short-hand for identifying the important groups. Race as measured by skin color is one of the most obvious potential markers. But these experiments showed that if skin color doesn't correlate with group boundaries, people very quickly learn to ignore it and look to other markers that do -- whether it's style of dress, manner of speaking, or what have you.

So I suspect that the social cost of diversity may in some sense be a psychic cost paid during the process of relearning markers that divide people into groups in a socially useful way. When diversity increases, there's social chaos and shifting boundaries; evolving group affiliations don't necessary follow the lines of the old markers, and so it is more difficult with ethnic markers alone to know who to trust. Hence, trust drops off even between those who share the old ethnic markers.

That's pure speculation on my part. I hope Putnam's or someone else's future work sheds more light. Kate has also offered a number of interesting comments on my last post, well worth a read. The ultimate question is how to manage immigration sensibly. It looks as if we just don't know enough yet to be sure, but Putnam's work clearly suggests, I think, that managing the rate of immigration is probably a good idea. Too much change too rapidly creates trouble.

Ethnic diversity: good or bad?

My agent Kerry Nugent Wells kindly alerted me to an article in the Boston Globe, covering the recent work of Harvard political scientist Robert Putnam. Putnam is justifiably famous for his great book Bowling Alone, which explored how social activity and civic-mindedness in all forms have dwindled away in the U.S. over the past half-century. He's a very careful researcher, and presented masses of data showing how U.S. society has begin strongly "atomized" in recent decades (which, by the way, has nothing whatsoever to do with my use of the word "atom" in The Social Atom).

The thesis of a new study just published by Putnam (in the journal Scandinavian Political Studies, as you'd of course expect!) is that ethnic diversity -- having lots of people from different races and cultures in the same community -- isn't the unfailingly positive social situation that many people take it to be. It brings a lot of problems too, especially a generalized decay of social cohesion and trust. Here's the abstract, which summarizes his findings pretty clearly:

Ethnic diversity is increasing in most advanced countries, driven mostly by sharp increases in immigration. In the long run immigration and diversity are likely to have important cultural, economic, fiscal, and developmental benefits. In the short run, however, immigration and ethnic diversity tend to reduce social solidarity and social capital. New evidence from the US suggests that in ethnically diverse neighbourhoods residents of all races tend to ‘hunker down’. Trust (even of one's own race) is lower, altruism and community cooperation rarer, friends fewer. In the long run, however, successful immigrant societies have overcome such fragmentation by creating new, cross-cutting forms of social solidarity and more encompassing identities. Illustrations of becoming comfortable with diversity are drawn from the US military, religious institutions, and earlier waves of American immigration.


Apparently - at least the article in The Globe takes this angle -- this study represents something of an "inconvenient truth" for many liberals committed to greater diversity. I'm not sure if that's true or not, but conservative commentators will almost certainly make a big deal of it. I'm reading the paper now (it's available here); let me just kind of write down some notes.

He first points to lots of studies, mostly in economics, showing that in the long run, ethnic diversity is a good thing; it leads to lots of creative energy born out of the mingling and combination of cultural habits. This doesn't seem to be contentious. What is less clear, and more contentious, is what happens in the short run, and specifically, what does diversity do for "social capital" -- the spontaneous sociability of people, which is a great resource for cooperative action?

As Putnam points out, there are two BIG IDEAS in social science on this point, and they conflict. The "contact hypothesis" holds that if you put different people in contact, they'll start to learn to get along and be less prejudiced toward one another. In contrast, the "conflict hypothesis" holds that in-group versus out-group prejudices are just too deeply ingrained, and contact just leads to more conflict. Is there more evidence for either of these? Apparently so:

For progressives, the contact theory is alluring, but I think it is fair to say that most (though not all) empirical studies have tended instead to support the so-called ‘conflict theory’, which suggests that, for various reasons – but above all, contention over limited resources – diversity fosters out-group distrust and in-group solidarity. On this theory, the more we are brought into physical proximity with people of another race or ethnic background, the more we stick to ‘our own’ and the less we trust the ‘other’...


Putnam's own study weighs in on these two opposing ideas, but comes out with a paradoxical conclusion -- that neither of them is quite right. Using a huge database of fairly recent survey data, he looked at the levels of trust between people in more or less ethnically diverse communities. (I'd insert some of his figures here, if I knew how to cut and paste into Blogger from a pdf file, but I don't.) First, he found not surprisingly that the level of trust between people of different races decreased with increasing diversity. This supports to conflict theory:

The more ethnically diverse the people we live around, the less we trust them. This pattern may be distressing normatively, but it seems to be consistent with conflict theory.


But wait.

Other data came from surveys asking people whether they trusted the people in their own neighbourhood, who, because of the norm of racial segregation, would tend to be of the same race. This data showed the same trend -- less trust with more diversity. Putnam then also looked at trust between people of the same race, and again finds the same trend -- less trust with more diversity. In conclusion, the data...

suggests that neither conflict theory nor contact theory corresponds to social reality in contemporary America. Diversity seems to trigger not in-group/out-group division, but anomie or social isolation.


Putnam goes on in the paper to adduce lots of other evidence supporting this basic conclusion, such as systematically lower confidence in political leaders, news media, government and so on. He also tries to control for every other conceivable variable that might lie behind the trend, such as correlations between diversity and community wealth, etc. The finding still stands. One final quote to bring home the message:

...inhabitants of diverse communities tend to withdraw from collective life, to distrust their neighbours, regardless of the colour of their skin, to withdraw even from close friends, to expect the worst from their community and its leaders, to volunteer less, give less to charity and work on community projects less often, to register to vote less, to agitate for social reform more, but have less faith that they can actually make a difference, and to huddle unhappily in front of the television.


This is a fascinating finding, and I'm not yet sure what to make of it. I'm also running behind on several other pressing matters, so I'm going to have to stop here for today.

It's important to point out that Putnam's data shows this antagonism between diversity and social cohesion in the short term, and doesn't imply that its locked in and unchangeable. Indeed, while there's lots of good evidence that while we're biologically hard-wired to divide people into groups, and to use those groups in our decision-making, the lines along which we divide them are not fixed.

But the biggest puzzle for me in this finding is why even people of the same group come to trust each other less in ethnically diverse communities. That's interesting, and puzzling, and Putnam doesn't seem to know the answer.

Wednesday, August 8, 2007

James Hansen -- Declaration of Stewardship

As you all know, the Bush Administration tried hard to keep NASA climate scientist James Hansen from speaking out publically about climate change. Fortunately they didn't succeed, and he's still speaking. Last week Hansen gave a speech in Des Moines Iowa, outlining what he calls a Declaration of Stewardship that any candidate serious about preserving our environment ought to endorse.

The speech (it's only three pages) is well worth a read, and I think it would be great if his proposed Declaration could somehow get enough attention that candidates actually started talking about it. It's surely depressing to contemplate the vast array of special interests bent on doing nothing -- see, for example, this rare expose in Newsweek of The Deniers' powerful disinformation campaigns -- but Hansen still has some optimism:

The public must also lead in the solution of the global warming problem. Special interests may have wounded our democracy, but it is still alive and well enough. The founders of our democracy established a remarkable system giving a vote to the commonest of men equal to that of the richest and most powerful citizen. We all have the right to vote, and we should use that right wisely.

Most candidates are likely to give lip service to the objective of avoiding dangerous human-made climate change. We need a way to smoke out who's serious, who will give priority to preserving creation for today’s and future generations, and who, on the contrary, is subservient to special interests.


The Declaration, as Hansen describes it, has three points:

Declaration 1: Moratorium on Dirty Coal: I will support a moratorium on construction of coal-fired power plants that do not capture and store CO2.

In explanation of this first declaration, I note that it is, by far, the most important thing that must be done to stop global warming. There is more CO2 in coal than in all of the oil and gas in the ground. If we phase out coal use except where we capture the CO2, the problem will be more than half licked. To qualify as “clean coal”, most of the CO2 must be captured.

Declaration 2: A Price on Carbon Emissions. I will support a gradually rising price on carbon emissions, reflecting costs to the environment, with mechanisms to adjust the price that are economically sound. A first step will be to eliminate subsidies of fossil fuels.

In explanation, the carbon price provides an effective way to support energy efficiency, conservation, renewable energy, nuclear power, and other low carbon energies, allowing these to compete against each other and permitting local choices. I note that the price on emissions does not need to be large, but business must recognize that it will be rising. This will unleash innovation. ...

Declaration 3: Increased energy efficiency and no-carbon energy sources. I will support effective actions to increase energy efficiency and conservation, remove barriers to efficiency, and increase use of low-carbon and no-carbon energy sources.

In explanation, there is great potential in energy efficiency, enough to satisfy near-term energy needs despite the moratorium on dirty coal, but barriers to efficiency must be removed. ... Actions under Declaration 3, in the absence of a moratorium on dirty-coal power-plants and a carbon price, cannot solve the climate problem and cannot save Creation. By themselves, increased efficiency and increased use of renewable or no-carbon energy lower the price of fossil fuels, assuring that the fossil fuels will be mined and used. The fact is that there are enough fossil fuels to destroy Creation unless a price is attached to carbon emissions.


Please forward to your favorite (or least favorite) candidate...

Monday, August 6, 2007

Social infinity...


The image to the left (which I've borrowed from a website on social psychology) shows world population versus time, and has two obviously striking features. First, the number of people stayed almost constant for eons stretching into the remote past, only beginning a slow upward trend a few thousand years ago. Second, something definitively spectacular happened about 200 years ago, which has led to an explosion of human numbers that still shows no signs of abating. In strictly mathematical terms, in fact, our population looks set to become infinite in the next half century (seriously, that's what the mathematics says according to some analyses; but more on that below).

What was is that happened? Essentially, science -- and technology. Medicine and knowledge about the causes of disease. Techniques to farm more food more reliably. Machinery to travel and subdue nature. Machinery to make better machinery. Etc. But what really made that happen -- that shift from earlier agrarian lifestyles to more modern economic enterprise? Apparently, this is still a point of serious contention among historians, anthropologists and economists, raising as much debate as our likely future.

One new proposed idea comes in A Farewell to Alms, a book due out next month by historian Gregory Clark of the University of California at Davis. His thesis, as summarized in a review in the New York Times, is that

...the Industrial Revolution — the surge in economic growth that occurred first in England around 1800 — occurred because of a change in the nature of the human population. The change was one in which people gradually developed the strange new behaviors required to make a modern economy work. The middle-class values of nonviolence, literacy, long working hours and a willingness to save emerged only recently in human history, Dr. Clark argues.


To be accurate, Clark isn't actually trying to explain the surge in population, but the sudden shift in economic prosperity that, in fact, didn't hit all nations equally. Still, there's an undeniable correlation between the population explosion and economic growth; indeed, a graph of GDP per capita doesn't look much different to that of population, showing the same marked rise after around 1500-1700, clearly linked to the increasingly effective use of technology. What Clark argues is that these shifts were actually caused by some significant change in the nature of people and their social habits.

And he suggests that an evolutionary process was at work. As The Times article continues,

Generation after generation, the rich had more surviving children than the poor, his research showed. That meant there must have been constant downward social mobility as the poor failed to reproduce themselves and the progeny of the rich took over their occupations. "The modern population of the English is largely descended from the economic upper classes of the Middle Ages," he concluded.

As the progeny of the rich pervaded all levels of society, Dr. Clark considered, the behaviors that made for wealth could have spread with them. He has documented that several aspects of what might now be called middle-class values changed significantly from the days of hunter gatherer societies to 1800. Work hours increased, literacy and numeracy rose, and the level of interpersonal violence dropped.


In the language of The Social Atom, Clark claims that the Industrial Revolution resulted primarily from evolutionary change in the social atom, its nature and habits, and not as an abrupt transformation or phase transition in collective social dynamics. Of course, individual habits and collective outcomes are closely linked, but what I think he's arguing is that it was evolutionary changes in the individual, first, which triggered massive collective change, not vice versa.

Logically speaking, I can see nothing to rule out such an idea, although I also don't find it strongly persuasive. My primary objection (as someone who has not read the book, mind you!) is that Clark seems to be thinking of evolution as genetic evolution, which was certainly taking place in the human population then, as it is now, but which generally takes a long periods of time to operate. More likely would be a form of cultural evolution, in which learned behaviors ("acquired characteristics," in biological terms) get passed down through generations by teaching and habit. Cultural evolution does happen quickly; look at how attitudes about the equality of men and women, or the races, have changed in 50 years, or how the nature of children's games has been transformed in 20 years. This is the kind of evolution that transforms a world in two centuries.

But if you go over to cultural evolution, it seems to me, Clark's thesis ceases to be radical and looks a lot more like the alternative view that it was change in social institutions, i.e. in the social patterns that constrain and direct our individual lives that were most important. Pattern more than people, in the phrase I like to overuse.

I have no evidence for it, but my guess is that the industrial revolution was more in the way of a socio-technological phase transition; a gathering and multiplying of technologies and know how that fed upon itself, ultimately driving a qualitative change in social activity and organization. New technology doesn't just let us do more things, and easier, but lets us invent more new technologies. Scientific advance doesn't give us only understanding and technology, but also new ways to do science -- to learn more even faster.

But whatever the cause, we're coming to the end of that era. At least that's what the mathematics seems to suggest. A few years ago, physicists Anders Johansen and Didier Sornette looked at the data for world population growth, and found that it has actually been considerably faster than exponential; indeed, the most natural mathematical fit is a curve that goes to infinity in the next 50 years. As they put it,

Contrary to common belief, both the Earth's human population and its economic output have grown faster than exponential, i.e., in a super-Malthusian mode, for most of the known history. These growth rates are compatible with a spontaneous singularity occuring at the same critical time 2052 +- 10 signaling an abrupt transition to a new regime.


In physics, whether in quantum field theory, general relativity or anywhere else, the appearance in a theory of an infinity -- a "spontaneous singularity" -- means that the theory breaks down. It suggests that something that hasn't been operating under ordinary conditions will come into play there and keep things finite. If the mathematics of Johansen and Sornette is right, then there's another social phase transition in the near future. (Of course, you don't really need mathematics to be convinced of that.)

puzzlement....

I'm having real difficulty believing what I just read. Maybe I need to think some more about the logic of inconsistency, and how politicians can strategically place themselves all across the policy spectrum to appeal to the many all at once. At a meeting of young Republicans, Newt Gingrich, of all people, seems to have addressed the followers in what anyone would objectively describe as liberal (and reality-based) terms. As Julia Dahl reports at Salon,

He began benignly enough, using an anecdote about going to Disney World with his grandchildren to explain an epiphany he'd had about the value of not "thinking like a Republican." From there Gingrich moved into waters the students surely did not expect. He cited the Detroit school system, where a black male is more likely to go to prison than graduate from high school.

"How can we tolerate systems more likely to send young Americans to prison than college?" asked Gingrich. "Republicans have this maniacally dumb idea of red versus blue. They say Detroit is a blue place, so we're not going to go there."

And he was just getting started.

"Republican political doctrine has been a failure," Gingrich said. "Look at New Orleans. How can you say that was a success? Look at Baghdad ... We've been in charge for six years and I don't think you can look around and say that was a great success.

"We have got to get beyond this political bologna. I'm not allowed to say anything positive about Hillary Clinton because then I'm not a loyal Republican, and she's not allowed to say anything positive about me because then she's not a loyal Democrat. What a stupid way to run a country." This last line he nearly spat out, expressing what seemed like genuine outrage. But the response was muted. Tepid applause bubbled up and then died within seconds.

Inhofe had recommended the students read Michael Crichton's "State of Fear" to learn about the global warming hoax, but Gingrich suggested they pick up newly elected French Prime Minister Nicolas Sarkozy's "Testimony."

And finally, when it seemed he'd been as blasphemous as he could possibly be, Gingrich pulled out a whopper: "None of you should believe we are winning this war," he said, referring to the so-called war on terror. "We are in a phony war ... we have not been taking this seriously."

When his speech was over, the students stood and applauded politely, but the volume was distinctly lower than it had been just an hour before.


What do you make of that?

Friday, August 3, 2007

The physics of crowds

In thinking of "social" behavior, we usually think of interactions with friends and community, social norms and so on. But these are fairly complicated human phenomena. In simplest terms, "social" merely implies some interaction between people, and maybe the simplest example is just walking around. You can walk on your own, as a lonely social atom wandering through empty space, or you can walk in the presence of others -- in which case interesting things start to happen.

In a post a while back I explored the curious phenomenon of lane formation in a street or hallway, whereby people walking with their own independent aims nevertheless segregate into well-defined lanes moving in either direction. There's a fascinating simulation of the process on the (old) website of the German physicist Dirk Helbing. Yesterday, in the course of some other research, I came upon some more recent work of Helbing's on human stampedes, in which people in the collective seem to follow physics that is eerily similar to that of the molecules in a fluid.

At least once a year, human stampedes seem to cause several hundred deaths. Most prominently are the almost routine problems during the Hajj (pilgrimage to Mecca) in Saudi Arabia. On 12 January, 2006, about 350 people died, while back in 1990 a similar crush killed almost 1500. Obviously, you can't do experiments with real people to see what causes these catastrophes.

Helbing, working with several Saudi scientists, has instead undertaken the analysis of video, where they can follow the motions of thousands of people in great detail, and then study the mathematics of their movements -- both in relatively normal flow conditions, and in times of crisis -- to clarify the differences. What they've already found is that the crowd at times undergoes a spontaneous transformation from regular ordered flow, akin to that of a fluid moving steadily within a pipe, to a turbulent flow characterized by enormous fluctuations -- irregular and chaotic motions within the crowd with the power to injure people.

Here's a fairly disturbing description of what happens, which they quote from earlier observations of other researchers:

At occupancies (crowd densities) of about 7 persons per square meter, the crowd becomes almost a fluid mass. Shock waves can be propeled through the mass, sufficient to... propel them distances of 3 meters or more... People may be literally lifted out of their shoes, and have clothing torn off. Intense crowd pressures, exacerbated by anxiety, make it difficult to breathe, which may finally cause compressive asphyxia. The heat and thermal insulation of surrounding bodies cause some to be weakened and faint. Access to those who fall is impossible.


The frightening thing is how utterly inhuman this description is; the people here simply do not have free will, but act as mechanical parts in a system, in this case in extreme conditions, which pushes them about according to its own collective forces.

Interestingly, and hopefully, the research of Helbing and colleagues shows that more mathematical scrutiny of such events may indeed help us understand these collective forces and learn to manage them. As they note, critical crowd conditions -- those that lead to real danger -- aren't obvious. Monitoring the average crowd density isn't enough, because there are often local fluctuations that produce much higher densities. Moreover, the most important quantity emerging from the video analysis isn't the density, but a slightly more abstract quantity -- the variance of people's moving speeds (how much they differ in a region) multiplied by the density, which plays the role of a pressure. Monitoring this pressure, which is what really leads to human damage, can help identify the places and moments when real trouble threatens. As they note, for example,

The crowd accident on January 12, 2006 started about 10 minutes after turbulent crowd motion set in, i.e. after the pressure exceeded a [critical] value...


They suggests that this pressure could be monitored (and rapidly calculated) from automatic video recordings.

As grisly and frightening as this example is, I think it illustrates with remarkable clarity how we can lose control over our own lives to stronger collective forces, even in this simplest of all social settings.

Wednesday, August 1, 2007

See what you like...


One of the topics I touch on in The Social Atom is the embarrassingly loose relationship between observations and beliefs in social science, especially among those driven by ideology. I've always thought it odd that there are "conservative" and "liberal" economists, when economists are supposed to be scientists approaching the workings of economic systems with the same dispassionate methods as physical scientists do nature (or so I thought). Nothing can send you toward ridiculous conclusions more rapidly than a conviction that you already know the truth.

Here's a most amusing example that I came across at Cosmicvariance (linking to Mark Thoma and Brad Delong). A while back, apparently, the Wall Street Journal, soon to be Rupert Murdoch's prize possession, published the figure above to illustrate the relationship between corporate tax rates and GDP. The Laffer curve is a theoretical construct (held in great respect by "conservative" economists) which purports to depict how the amount of overall tax revenue a nation collects first rises with increasing tax rates, and then ultimately falls -- showing how too-high taxes can be bad for the economy.

The Journal published this figure, fitting the Laffer Curve to the data for a number of real countries, apparently with a straight face. Or were they laffing? It doesn't take immense mathematical intuition to doubt whether the curve really matches the data very well; it certainly doesn't look like it.


Here, in contrast, is Mark Thoma's rather more realistic attempt at fitting the data with a relatively simple curve. I think most physical scientists would look at this and say that this curve too is rather hard to take seriously; what the data really seems to show is an awful lot of scatter, suggesting that the tax rate alone just doesn't account for much of the variation in tax collected. Other factors must be more important.

But Thoma's curve (and he offered only as an illustration of how easy it is to do better than the WSJ's completely ludicrous fitting) at least isn't a purposeful distortion of reality. Oh, but perhaps we shouldn't be surprised. Apparently the "original" research quoted in the WSJ editorial was carried out by economist Kevin Hassett at the American Enterprise Institute, self-proclaimed to be "a private, nonpartisan, not-for-profit institution dedicated to research and education on issues of government, politics, economics, and social welfare."

I'm not sure what Dr Hassett learned about curve fitting during his education, and experience, which certainly seems impressive. From the AEI website:

Before joining AEI, Hassett was a senior economist at the Board of Governors of the Federal Reserve System and an associate professor of economics and finance at the Graduate School of Business of Columbia University. He was an economic adviser to the George W. Bush campaign in the 2004 presidential election and the chief economic adviser to Senator McCain during the 2000 presidential primaries. He has also served as a policy consultant to the Treasury Department during the former Bush and Clinton administrations.


Worrying, eh?