Monday, December 27, 2010

Podcast roundup

Econtalk: Joe Nocera and Russ Roberts discuss the financial crisis. One of the best Econtalk podcasts in a long time. I think I agreed entirely with Nocera.

In Our Time on the Industrial Revolution. Ordinarily deferential host Melvyn Bragg mixes it up with guests over UK exceptionalism. Was it primarily easy access to coal, or were other factors as important?

Christmas eve gospel: Mahalia Jackson rules! Tracks 1, 14 and 15 are my favorites. It's a shame we almost never hear this kind of music any more.

John Mellencamp on Fresh Air. Highly recommended if you are a fan. This is an old interview, but I only listened to it relatively recently.

Saturday, December 25, 2010

The mystery of height

Academia Sinica (where I am on sabbatical) has a small bookstore that my kids always drag me to. Ordinarily I am happy to spend embarrassingly large amounts of time at a bookstore, but this place has only a small collection of English books. Over time, I think I've flipped through most of them! Yesterday I was looking at The Formosan Encounter: Notes on Formosa's Aboriginal Society, A Selection of Documents from Dutch Archival Sources. The Dutch came to Taiwan (then called Formosa) in the early 17th century and these translated documents record their impressions of the Austronesian natives. (Both the Dutch and Chinese settlers traded with the natives during this period.)

One report states that the aboriginal men were taller by a head and neck, on average, than the Dutch. (The average Dutchman came only to the shoulder of the average native?) Another report describes the aborigines as tall and sturdily built, like semi-giants. This paper on historical Dutch height suggests that 17th century Dutchmen were about 170 cm or so on average. Holland was the richest country in Europe at the time, but nutritional conditions for average people were still not good by modern standards. So how tall were the aborigines? Presumably well above 180cm since "a head and neck" would be at least 20cm! (Some Native Americans were also very tall when the Europeans first encountered them.)

But, strangely, the descendants of these aborigines are not known for being particularly tall. This paper reports that modern day aboriginal children in Taiwan are shorter than their Han counterparts. On the other hand, the Dutch are now the tallest people in the world, with average male height exceeding 6 feet (183 cm). This kind of reversal makes one wonder whether, indeed, most groups of humans have similar potential for height under ideal conditions, as claimed here. (Note the epigenetic effects -- several generations of good nutrition might be required for a group to reach its full height.)

In the nineteenth century, when Americans were the tallest people in the world, the country took in floods of immigrants. And those Europeans, too, were small compared with native-born Americans. Malnourishment in a mother can cause a child not to grow as tall as it would otherwise. But after three generations or so the immigrants catch up. Around the world, well-fed children differ in height by less than half an inch.* In a few, rare cases, an entire people may share the same growth disorder. African Pygmies, for instance, produce too few growth hormones and the proteins that bind them to tissues, so they can’t break five feet even on the best of diets. By and large, though, any population can grow as tall as any other.

* I'm not sure where this statement comes from, since, for example, Japanese still seem to be a few inches shorter than, say Europeans. But it's also true that even the modern Japanese diet is lower in protein and calcium than the corresponding European or American one.

Taiwan photos 7: Merry Xmas!

This is what happens when I try to take a Christmas photo of the kids :-)

No, it's not a set from Alien, it's a futuristic mega mall where we did some shopping.

Thursday, December 23, 2010

Peace on Earth, Good Will to Men 2010

Linus said it best in A Charlie Brown Christmas (Luke 2.14):

And there were in the same country shepherds abiding in the field, keeping watch over their flock by night.

And, lo, the angel of the Lord came upon them, and the glory of the Lord shone round about them: and they were sore afraid.

And the angel said unto them, Fear not: for, behold, I bring you good tidings of great joy, which shall be to all people.

For unto you is born this day in the city of David a Saviour, which is Christ the Lord.

And this shall be a sign unto you; Ye shall find the babe wrapped in swaddling clothes, lying in a manger.

And suddenly there was with the angel a multitude of the heavenly host praising God, and saying,

Glory to God in the highest, and on earth peace, good will toward men.

Merry Christmas!

More ancient DNA

Another ancient hominid (not neanderthals, perhaps one of their contemporaries, or even an earlier erectus variant) appears to have interbred with humans. About 5% of Melanesian DNA appears to come from this hominid, whereas there seems to have been little or no interbreeding with the predecessors of groups such as Europeans, East Asians or Africans. Earlier results showed that modern Eurasians can trace a few percent of their DNA to Neanderthals.

NYTimes, Nature.

So, the following are true:

1. there were wildly divergent ancient hominids (in terms of development, skull shape, physiognomy) who could and did interbreed

2. different groups of modern humans have different distributions of ancient DNA as a consequence of this interbreeding

Much more discussion by Razib at the link below.

gnxp: ... When I was a freshman at university I took a biological anthropology course. The instructor threw out a question to the class. He noted that some paleoanthropologists observed a continuity between the skulls of Australian Aborigines and some Southeast Asian erectine populations. Australian Aborigines are a very robust people, and have been less affected by the trend toward gracility which has been the norm over the past 10,000 years for most human populations. In any case, the instructor asked for a show of hands whether such a possibility should even be discussed openly. The solid majority of the class rejected an open discussion. When asked by the instructor why, many of the students who rejected an examination of the thesis argued that such a possibility opened the path to de-humanization, oppression, and was politically too sensitive. Milford Wolpoff had obviously lost the propaganda war. The students did not consider the possibility of multiregionalism where all human populations exhibited continuity, rather, they assumed that continuity hypothesized for Australian Aborigines was specific to them, and so would associate that population with the less human branches of the hominin tree.

Full Attention: best scene from The Social Network

Silicon Valley Man meets Legal Man -- my favorite scene from The Social Network. Yes, Zuckerberg comes off as an ass, but it's what real startup guys think and feel.

You have part of my attention. You have the minimum amount. The rest of my attention is back at the offices of facebook, where my colleagues and I are doing things that no one in this room, including and especially your clients, are intellectually or creatively capable of doing. Did I adequately answer your condescending question?

Hedonic treadmill alert: bad enough that Zuckerberg is the youngest billionaire ever, Sean Parker is also worth nearly a billion!

I notice the movie didn't give out all the details of the Saverin settlement (rumor has it he got about $1 billion as well). See here for more background. Was it just me or did the whole thing seem like an advertisement for Harvard?

Tuesday, December 21, 2010

Scaling laws for cities

Shorter Geoff West on cities (isn't math great?): resource consumption scales sub-linearly with population, whereas economic output scales super-linearly.

Uncompressed version follows below and at link ;-)

NYTimes: ... After two years of analysis, West and Bettencourt discovered that all of these urban variables could be described by a few exquisitely simple equations. For example, if they know the population of a metropolitan area in a given country, they can estimate, with approximately 85 percent accuracy, its average income and the dimensions of its sewer system. These are the laws, they say, that automatically emerge whenever people “agglomerate,” cramming themselves into apartment buildings and subway cars. It doesn’t matter if the place is Manhattan or Manhattan, Kan.: the urban patterns remain the same. West isn’t shy about describing the magnitude of this accomplishment. “What we found are the constants that describe every city,” he says. “I can take these laws and make precise predictions about the number of violent crimes and the surface area of roads in a city in Japan with 200,000 people. I don’t know anything about this city or even where it is or its history, but I can tell you all about it. And the reason I can do that is because every city is really the same.” After a pause, as if reflecting on his hyperbole, West adds: “Look, we all know that every city is unique. That’s all we talk about when we talk about cities, those things that make New York different from L.A., or Tokyo different from Albuquerque. But focusing on those differences misses the point. Sure, there are differences, but different from what? We’ve found the what.”

There is something deeply strange about thinking of the metropolis in such abstract terms. [REALLY?!?] We usually describe cities, after all, as local entities defined by geography and history. New Orleans isn’t a generic place of 336,644 people. It’s the bayou and Katrina and Cajun cuisine. New York isn’t just another city. It’s a former Dutch fur-trading settlement, the center of the finance industry and home to the Yankees. And yet, West insists, those facts are mere details, interesting anecdotes that don’t explain very much. The only way to really understand the city, West says, is to understand its deep structure, its defining patterns, which will show us whether a metropolis will flourish or fall apart. We can’t make our cities work better until we know how they work. And, West says, he knows how they work.

West has been drawn to different fields before. In 1997, less than five years after he transitioned away from high-energy physics, he published one of the most contentious and influential papers in modern biology. (The research, which appeared in Science, has been cited more than 1,500 times.) The last line of the paper summarizes the sweep of its ambition, as West and his co-authors assert that they have just solved “the single most pervasive theme underlying all biological diversity,” showing how the most vital facts about animals — heart rate, size, caloric needs — are interrelated in unexpected ways.

... In city after city, the indicators of urban “metabolism,” like the number of gas stations or the total surface area of roads, showed that when a city doubles in size, it requires an increase in resources of only 85 percent.

This straightforward observation has some surprising implications. It suggests, for instance, that modern cities are the real centers of sustainability. According to the data, people who live in densely populated places require less heat in the winter and need fewer miles of asphalt per capita. (A recent analysis by economists at Harvard and U.C.L.A. demonstrated that the average Manhattanite emits 14,127 fewer pounds of carbon dioxide annually than someone living in the New York suburbs.) Small communities might look green, but they consume a disproportionate amount of everything. As a result, West argues, creating a more sustainable society will require our big cities to get even bigger. We need more megalopolises.

But a city is not just a frugal elephant; biological equations can’t entirely explain the growth of urban areas. While the first settlements in Mesopotamia might have helped people conserve scarce resources — irrigation networks meant more water for everyone — the concept of the city spread for an entirely different reason. “In retrospect, I was quite stupid,” West says. He was so excited by the parallels between cities and living things that he “didn’t pay enough attention to the ways in which urban areas and organisms are completely different.”

What Bettencourt and West failed to appreciate, at least at first, was that the value of modern cities has little to do with energy efficiency. As West puts it, “Nobody moves to New York to save money on their gas bill.” Why, then, do we put up with the indignities of the city? Why do we accept the failing schools and overpriced apartments, the bedbugs and the traffic?

In essence, they arrive at the sensible conclusion that cities are valuable because they facilitate human interactions, as people crammed into a few square miles exchange ideas and start collaborations. “If you ask people why they move to the city, they always give the same reasons,” West says. “They’ve come to get a job or follow their friends or to be at the center of a scene. That’s why we pay the high rent. Cities are all about the people, not the infrastructure.”

It’s when West switches the conversation from infrastructure to people that he brings up the work of Jane Jacobs, the urban activist and author of “The Death and Life of Great American Cities.” Jacobs was a fierce advocate for the preservation of small-scale neighborhoods, like Greenwich Village and the North End in Boston. The value of such urban areas, she said, is that they facilitate the free flow of information between city dwellers. To illustrate her point, Jacobs described her local stretch of Hudson Street in the Village. She compared the crowded sidewalk to a spontaneous “ballet,” filled with people from different walks of life. School kids on the stoops, gossiping homemakers, “business lunchers” on their way back to the office. While urban planners had long derided such neighborhoods for their inefficiencies — that’s why Robert Moses, the “master builder” of New York, wanted to build an eight-lane elevated highway through SoHo and the Village — Jacobs insisted that these casual exchanges were essential. She saw the city not as a mass of buildings but rather as a vessel of empty spaces, in which people interacted with other people. The city wasn’t a skyline — it was a dance.

If West’s basic idea was familiar, however, the evidence he provided for it was anything but. The challenge for Bettencourt and West was finding a way to quantify urban interactions. As usual, they began with reams of statistics. The first data set they analyzed was on the economic productivity of American cities, and it quickly became clear that their working hypothesis — like elephants, cities become more efficient as they get bigger — was profoundly incomplete. According to the data, whenever a city doubles in size, every measure of economic activity, from construction spending to the amount of bank deposits, increases by approximately 15 percent per capita. It doesn’t matter how big the city is; the law remains the same. “This remarkable equation is why people move to the big city,” West says. “Because you can take the same person, and if you just move them to a city that’s twice as big, then all of a sudden they’ll do 15 percent more of everything that we can measure.” While Jacobs could only speculate on the value of our urban interactions, West insists that he has found a way to “scientifically confirm” her conjectures. “One of my favorite compliments is when people come up to me and say, ‘You have done what Jane Jacobs would have done, if only she could do mathematics,’ ” West says. “What the data clearly shows, and what she was clever enough to anticipate, is that when people come together, they become much more productive.” ...

The gentry

Meanwhile we continue to maim and destroy some of our best young men for no good reason. Via Maoxian.
New Republic: A few years ago, when I was still teaching at the University of Chicago, I had my first Chinese graduate students, a couple of earnest Beijingers who had come to the Committee on Social Thought hoping to bump into the ghost of Leo Strauss, the German-Jewish political philosopher who established his career at the university. Given the mute deference they were accustomed to giving their professors, it was hard to make out just what these young men were looking for, in Chicago or Strauss. They attended courses and worked diligently, but otherwise kept to themselves. They were in but not of Hyde Park.

At the end of their first year, I called one of them into my office to offer a little advice. He was obviously thoughtful and serious, and was already well known in Beijing intellectual circles for his writings and his translations of Western books in sociology and philosophy into Chinese. But his inability to express himself in written or spoken English had frustrated us both in a course of mine he had just taken. I began asking about his summer plans, eventually steering the conversation to the subject of English immersion programs, which I suggested he look into. “Why?” he asked. A little flummoxed, I said the obvious thing: that mastering English would allow him to engage with foreign scholars and advance his career at home. He smiled in a slightly patronizing way and said, “I am not so sure.” Now fully flummoxed, I asked what he would be doing instead. “Oh, I will do language, but Latin, not English.” It was my turn to ask why. “I think it very important we study Romans, not just Greeks. Romans built an empire over many centuries. We must learn from them.” When he left, it was clear that I was being dismissed, not him.

This conversation came to mind recently after I returned from a month of lectures and interviews in China. I had heard that Strauss was popular there, as was, to my surprise, Carl Schmitt, the Weimar anti-liberal (and anti-Semitic) legal theorist. The New Yorker had even run a piece that spoke of “the new generation’s neocon nationalists,” mentioning the interest in Strauss as some sort of disturbing development. What I discovered, especially among the many young people I spoke with, was something much more interesting and important. Strauss and Schmitt are at the center of intellectual debate, but they are being read by everyone, whatever their partisan leanings; as a liberal journalist in Shanghai told me as we took a stroll one day, “no one will take you seriously if you have nothing to say about these two men and their ideas.” And the interest has little to do with nationalism in the nineteenth-century sense of the term. It is a response to crisis—a widely shared belief that the millennia-long continuity of Chinese history has been broken and that everything, politically and intellectually, is now up for grabs.

... Liberal thought, the young ones now feel, just doesn’t help them understand the dynamics of Chinese life today or offer a model for the future. For example, everyone I spoke with, across the political spectrum, agrees that China needs a stronger state, not a weaker one—a state that follows the rule of law, is less capricious, can control local corruption, and can perform and carry out long-term planning. Their disagreements all seem to be about how a strong state should exercise its power over the economy and how its newfound power should be exercised in international affairs. Similarly, there was complete consensus about China’s right to defend its national interests, just differences over what those interests are. When my turn to talk about American politics came, and I tried to explain the Tea Party movement’s goal of “getting government off our backs,” I was met with blank stares and ironic smiles.

... Classical liberalism sees society as having multiple, semi-autonomous spheres; Schmitt asserted the priority of the social whole (his ideal was the medieval Catholic Church) and considered the autonomy of the economy, say, or culture or religion, as a dangerous fiction. (“The political is the total, and as a result we know that any decision about whether something is unpolitical is always a political decision.”) Classical liberalism treats sovereignty as a kind of coin that individuals are given by nature and which they cash in as they build legitimate political institutions for themselves; Schmitt saw sovereignty as the result of an arbitrary self-founding act by a leader, a party, a class, or a nation that simply declares “thus it shall be.” Classical liberalism had little to say about war and international affairs, leaving the impression that, if only human rights were respected and markets kept free, a morally universal and pacified world order would result. For Schmitt, this was liberalism’s greatest and most revealing intellectual abdication: If you have nothing to say about war, you have nothing to say about politics. There is, he wrote, “absolutely no liberal politics, only a liberal critique of politics.”

... The Chinese tradition of political thought that begins with Confucius, though in a way statist, is altogether different: Its aim is to build a just social hierarchy where every person has a station and is bound to others by clear obligations, including the ruler, who is there to serve. Central to the functioning of such a state are the “gentlemen” (or “gentry” in some Confucius translations), men of character and conscience trained to serve the ruler by making him a better one—more rational and concerned with the people’s good. Though the Chinese students I met clearly wanted to épater their teachers and me by constantly referring to Schmitt, the truth is that they want a good society, not just a strong one.

Enter Leo Strauss, again. The most controversial aspect of Strauss’s thought in the United States over the past decade, given the role some of his devotees played in concocting the latest Iraq war, is what he had to say about the “gentleman.” Taking a cue from Aristotle, Strauss distinguished between philosophers, on the one hand, and practical men who embody civic virtue and are devoted to the public good, on the other: While knowing what constitutes the good society requires philosophy, he taught, bringing it about and maintaining it requires gentlemen. Aristocracies recognize this need, democracies don’t—which is why the education of gentlemen is difficult in democratic societies and may need to take place in secret. Much was made of this gentlemanly idea in Straussian circles after his death, and as young Straussians became part of the Republican foreign policy apparat, beginning in the Reagan administration, many began seeing themselves as members of an enlightened class guiding America through the “crisis of the West.” (This episode still awaits its satirist.) In this sense there was indeed a connection between Straussianism and the Iraq war.

But for the young Chinese I met, the distinction between sages and statesmen and the idea of an elite class educated to serve the public good make perfect sense because they are already rooted in the Chinese political tradition. What makes Strauss additionally appealing to them, apart from the grand tapestry of Western political theory he lays before them, is that he makes this ideal philosophically respectable without reference to Confucius or religion or Chinese history. He provides a bridge between their ancient tradition and our own. No one I met talked about a post-Communist China, for obvious reasons. But students did speak openly about the need for a new gentry class to direct China’s affairs, to strengthen the state by making it wiser and more just. None of them seemed particularly eager to join the Party, which they said co-opted even the most independent thinkers. For the moment, they seem content to study ancient languages, get their Ph.D.s, and take teaching jobs where they evidently hope to produce philosophers and gentlemen. They are not in a hurry. Rome wasn’t built in a day.

Saturday, December 18, 2010

Beijing photos 5: canyons of Zhongguancun

Took a little walk around this morning -- sunny and warm. This is the Tsinghua University Science Park, home of the Googlers and MSFT Research Beijing. Walking is healthy, but crossing an intersection in China means risking your life! 8-)

Friday, December 17, 2010

Beijing photos 4

We had a fancy conference banquet last night. I thought the decor of the restaurant was so nice I took some photos.

Wine room (not exactly a cellar).


Hostesses :-) (Homage to Maoxian!)

A picture of a distant relative of mine, found on the wall.

After dinner I rushed over to the Beijing Friendship hotel (near Renmin University) to meet with the most famous teacher of mathematical prodigies in China. When I arrived he was already talking with his former student, my BGI collaborator. BGI recently gave the Raven's Advanced Progressive Matrices to a sample of his students. (Stay tuned!) During our conversation, he bemoaned the number of his top pupils now working at banks and hedge funds. Given the economic conditions in China there is tremendous pressure on talented students to pursue money rather than a scientific career. (See below.)

Thursday, December 16, 2010

g at work

This is a caricature of about a dozen conversations I've had in the last few months, including today.

Colleague (physicist): What's this genomics stuff you're doing?

me: We're looking for genes associated with IQ or g. Sequencing costs are going down at ...

physicist: Yes, yes, super-exponential rate. IQ, is that like those Mensa clowns? What's g?

me: Actually the research results are pretty clear...

physicist: Aren't there lots of independent cognitive abilities? Like memory, geometric visualization, vocabulary, etc.?

me: Yes, but it turns out they are all positively correlated. Suppose there are N abilities; represent each person as a point in the N dimensional space. The population distribution is like an ellipsoid and the longest axis is what they call g. It turns out g has a lot of predictive power...

physicist: Oh, I get it. Neat! Can I be in your study?

Below are responses from analogous conversations I've had with different, uh, kinds of people (like other kinds of, uh, scientists ;-)

Sequencing costs? Sequencing what?

IQ? That was all discredited by Stephen J. Gould!

Aren't the scores just determined by the SES of the parents?

N dimensional what?!?

Note added: I hereby apologize for any psychological trauma my post may have inflicted on others :-/

Beijing photos 3

I gave another talk this morning on monsters. I'm the only speaker here using English -- all the other talks are in Chinese. My Mandarin is not good enough to follow physics talks (not even close). It is quite interesting how much is lost even though the slides are mostly in English. Despite weird claims I've read that Chinese is not precise enough for science (or whatever), people here seem to have no trouble doing physics entirely in Chinese, with only the occasional technical term thrown in: "spacelike", "Killing vector", etc. I learned the Mandarin word for "entropy" but then promptly forgot it :-(

I guess I have an inkling as to how hard it is for a graduate student from China to adapt to physics in the West.

One of the former PhD students from this institute (now a postdoc at McGill) told me that in the better physics departments in China about 1/3 of the graduates get jobs in industry, 1/3 stay here to do PhDs, and about 1/3 go abroad, usually to US graduate programs (roughly 7 of the top 10 in his class went to the US; this would have been 5+ years ago).

Sorry for the lame photos -- you can tell I haven't strayed very far from my hotel and the physics institute. I notice the light is very beautiful in Beijing this time of year, at least when it's windy and the smog is dispersed. However, that wind makes it wickedly cold at night.

View from KITP; big red brick building is condensed matter physics.

Inside KITP.

Li Miao derives the Einstein equations from entropic considerations.

Audience is shocked ;-)

Tuesday, December 14, 2010

QED theta angle

[ Note: see follow up paper here: ]

I finally posted the paper I've been working on. The claim will probably be controversial, so I tried to check my results carefully. But it's still possible that I've missed something.

Physical consequences of the QED theta angle

We describe a simple gedanken experiment which illustrates the physical effects of the QED theta angle, a fundamental parameter of Nature that has yet to be measured. The effects are manifest in quantum phases analogous to those in the Aharonov-Bohm effect, although they are not intrinsically topological. We also derive the quantum phases using a functional Schrodinger approach, and generalize the results to non-Abelian gauge theories.

The conventional thinking is that because FF-dual in QED is a total derivative, doesn't affect the classical equations of motion, and isn't related to any topological vacuum structure, it can't have physical consequences. However, I seem to be able to construct gedanken experiments in which there is a quantum mechanical effect: a relative phase that can lead to interference between photons. This is analogous to the Aharonov-Bohm effect, in which the electron phase is affected by the vector potential, even if there is no magnetic force on the electron.

I derive the effect first using the path integral, but also using the functional Schrodinger equation, which makes the A-B analogy more transparent. The presence of a theta term shifts the canonical momentum in QED, which shifts the momentum operator in the Schrodinger equation, and leads to a phase just as in A-B.

I'm giving a talk on this later today at the ITP/KITP Beijing. The slides are here.

My host told me I should have given it a sexier title like "New quantum phases in Abelian gauge theory" ... Kids these days ... :-)

Inside the Beijing bubble

Talking to the maid at my hotel.

me: Where are you from?

her: Hubei.

me: How long have you been in Beijing?

her: Only one month.

me: How do you like it?

her: Of course I like it! There is nothing to do in Hubei.

me: Are things tough in Hubei?

her: Not tough, but nothing to do. It's not easy to make money.

The hotel has a fancy gym -- it's a membership place, so hotel guests mingle with affluent Beijingers who presumably live or work near Zhongguancun (high tech / university / research district). I was shocked by the number of personal trainers. There were more people working out than trainers, but not by a huge margin. In China I often get these moments of disequilibrium where my economics-brain screams "labor surplus" and "massive income inequality". Then I remembered the last time I saw the same thing -- the upper east side of Manhattan :-)

The Beijingers (men and women) were not buff, but they were trying hard! I felt a little bit like Mike Katz in Pumping Iron (I am exaggerating, of course).

Mike Katz, hulking the lineup: "Sometimes when you're working out in the gym and you're so much more developed and, you know, unbelievable in comparison to anybody working out around you, you say to yourself, 'Man, am I real?'"

Sunshine in Beijing.

Money Talks! even at the Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing... :^)

Monday, December 13, 2010

Beijing photos 2

It was windy on Monday and today (Tuesday) so the air quality is much better than when I arrived. The pictures below are of the physics campus of the Chinese Academy of Sciences.

The tall building on the left is all condensed matter physics.

KITP Beijing (Kavli Institute) is the shorter red brick building on the right.

Last night I had Beijing duck with Seth Roberts. Seth has an interesting history. He started college at Caltech but transferred to Reed to study psychology. He was on the Berkeley faculty for many years but has moved to China and is now a professor at Tsinghua university. He knew Feynman and Jane Jacobs. We talked so long they closed down the restaurant around us!

If I recall correctly, Seth said the Tsinghua undergrads blow away the Berkeley undergrads he used to teach. He even said their ability to speak/write English was comparable(!), but perhaps it's a selected sub-population that would take a class taught in English.

Saturday, December 11, 2010

Beijing photos; the ant tribe

It's Sunday morning in Beijing. I arrived last night and am staying in a hotel in Zhongguancun, the Silicon Valley of China, which is also close to the two top universities -- Beida (Beijing University) and Tsinghua. The institute I am visiting (part of the Chinese Academy of Sciences) is a short walk from here.

Note the contrast between the nice hotel room and what is just outside. This is typical in China at the current level of development. Also note the pollution -- reminds me of LA in 1980s :-(

If you look carefully, you can see some dormitories near the center of the picture below. It's not temporary housing for construction workers -- I saw people coming in and out this morning, they are relatively young and include both men and women. ***

In an earlier post I discussed Shanghai PISA scores. Many people have the idea that Shanghai and Beijing are showcase cities -- unrepresentative of China as a whole. This is certainly true to a degree, but these are cities with populations of 20+ million people (larger than many countries in the PISA data). It's quite hard to raise the overall level of 20 million people. You don't have to look very hard in even the most developed parts of these places to see the grittier aspects of life here.

*** I seem to have discovered an ant colony -- a dwelling place for members of the "ant tribe" :-) The NYTimes is on the story (video):

BEIJING — Liu Yang, a coal miner’s daughter, arrived in the capital this past summer with a freshly printed diploma from Datong University, $140 in her wallet and an air of invincibility.

Her first taste of reality came later the same day, as she lugged her bags through a ramshackle neighborhood, not far from the Olympic Village, where tens of thousands of other young strivers cram four to a room.

Unable to find a bed and unimpressed by the rabbit warren of slapdash buildings, Ms. Liu scowled as the smell of trash wafted up around her. “Beijing isn’t like this in the movies,” she said.

... Chinese sociologists have come up with a new term for educated young people who move in search of work like Ms. Liu: the ant tribe. It is a reference to their immense numbers — at least 100,000 in Beijing alone — and to the fact that they often settle into crowded neighborhoods, toiling for wages that would give even low-paid factory workers pause.

“Like ants, they gather in colonies, sometimes underground in basements, and work long and hard,” said Zhou Xiaozheng, a sociology professor at Renmin University in Beijing.

The central government, well aware of the risks of inequitable growth, has been trying to channel more development to inland provinces like Shanxi, Ms. Liu’s home province, where the dismantling of state-owned industries a decade ago left a string of anemic cities.

Despite government efforts, urban residents earned on average 3.3 times more last year than those living in the countryside. Such disparities — and the lure of spectacular wealth in coastal cities like Shanghai, Tianjin and Shenzhen — keep young graduates coming.

“Compared with Beijing, my hometown in Shanxi feels like it’s stuck in the 1950s,” said Li Xudong, 25, one of Ms. Liu’s classmates, whose father is a vegetable peddler. “If I stayed there, my life would be empty and depressing.”

While some recent graduates find success, many are worn down by a gantlet of challenges and disappointments. Living conditions can be Dickensian, and grueling six-day work weeks leave little time for anything else but sleeping, eating and doing the laundry.

But what many new arrivals find more discomfiting are the obstacles that hard work alone cannot overcome. Their undergraduate degrees, many from the growing crop of third-tier provincial schools, earn them little respect in the big city. And as the children of peasants or factory workers, they lack the essential social lubricant known as guanxi, or personal connections, that greases the way for the offspring of China’s nouveau riche and the politically connected.

Emerging from the sheltered adolescence of one-child families, they quickly bump up against the bureaucracy of population management, known as the hukou system, which denies migrants the subsidized housing and other health and welfare benefits enjoyed by legally registered residents.

Add to this a demographic tide that has increased the ranks of China’s 20-to-25-year-olds to 123 million, about 17 million more than there were just four years ago.

“China has really improved the quality of its work force, but on the other hand competition has never been more serious,” said Peng Xizhe, dean of Social Development and Public Policy at Fudan University in Shanghai.

At the meeting I attended last month in Shanghai I asked a Beida PhD student if he knew people in the ant tribe. "Of course," he said. "A former classmate [physics major!] is one of those ants."

Friday, December 10, 2010

Beijing bound

Off to Beijing tomorrow. I'll be a visitor at ITP/KITP for the next week. I hope I have enough warm clothes. It will be a shock, since I've been walking around in shorts in Taipei!

Planning to meet up with Seth Roberts (a techer!), Maoxian, and assorted physicists, mathematicians, young prodigies, and genomicists :-)

Maoxian points me to this place, among others:

Tuesday, December 07, 2010

Shanghai PISA scores

The Shanghai math (+1 SD) and science (+.75 SD) scores are almost a full SD above the OECD average of 500 (SD = 100). The top 10 percent of Shanghai math students are all above the 99th percentile for the US. See earlier post for links to Rindermann's work relating school achievement tests like TIMSS and PISA to national IQ estimates, and see here for earlier SD estimates using 2006 PISA data. (Finland has an anomalously low SD in the earlier data. A quick look at the 2009 data shows the following math SDs: Finland 82, USA 91, Korea 89, Japan 94, Germany 98, Shanghai 103, Singapore 104.)

Although Shanghai and Beijing are the richest cities in China, incomes are still quite low compared to the US. Average income in Shanghai is about $10k USD per annum, even PPP adjusted this is about $20k. People live very modestly by the standards of developed countries.

As noted in the comments, there are other places in China that score *higher* than Shanghai on college entrance exams or in math and science competitions. So while Shanghai is probably above the average in China, it isn't as exceptional as is perhaps implied in the Times article.

Taiwan has been moving to an American-style, less test-centric, educational system in the last decade. Educators and government officials (according to local media reports in the last 12 hours) are very concerned about the "low scores" achieved in the most recent PISA :-)

To see how individual states or ethnicities in the US score on PISA, see here and here.

NYTimes: ... PISA scores are on a scale, with 500 as the average. Two-thirds of students in participating countries score between 400 and 600. On the math test last year, students in Shanghai scored 600, in Singapore 562, in Germany 513, and in the United States 487.

In reading, Shanghai students scored 556, ahead of second-place Korea with 539. The United States scored 500 and came in 17th, putting it on par with students in the Netherlands, Belgium, Norway, Germany, France, the United Kingdom and several other countries.

In science, Shanghai students scored 575. In second place was Finland, where the average score was 554. The United States scored 502 — in 23rd place — with a performance indistinguishable from Poland, Ireland, Norway, France and several other countries.

The testing in Shanghai was carried out by an international contractor, working with Chinese authorities, and overseen by the Australian Council for Educational Research, a nonprofit testing group, said Andreas Schleicher, who directs the Organization for Economic Cooperation and Development’s international educational testing program.

Mark Schneider, a commissioner of the Department of Education’s research arm in the George W. Bush administration, who returned from an educational research visit to China on Friday, said he had been skeptical about some PISA results in the past. But Mr. Schneider said he considered the accuracy of these results to be unassailable.

“The technical side of this was well regulated, the sampling was O.K., and there was no evidence of cheating,” he said.

Mr. Schneider, however, noted some factors that may have influenced the outcome.

For one thing, Shanghai is a huge migration hub within China. Students are supposed to return to their home provinces to attend high school, but the Shanghai authorities could increase scores by allowing stellar students to stay in the city, he said. And Shanghai students apparently were told the test was important for China’s image and thus were more motivated to do well, he said.

“Can you imagine the reaction if we told the students of Chicago that the PISA was an important international test and that America’s reputation depended on them performing well?” Mr. Schneider said. “That said, China is taking education very seriously. The work ethic is amazingly strong.”

... Ever since his organization received the Shanghai test scores last year, Mr. Schleicher said, international testing experts have investigated them to vouchsafe for their accuracy, expecting that they would produce astonishment in many Western countries.

“This is the first time that we have internationally comparable data on learning outcomes in China,” Mr. Schleicher said. “While that’s important, for me the real significance of these results is that they refute the commonly held hypothesis that China just produces rote learning.”

“Large fractions of these students demonstrate their ability to extrapolate from what they know and apply their knowledge very creatively in novel situations,” he said.

Saturday, December 04, 2010

Supercomputers and the mystery of IQ

This article appeared today in the South China Morning Post, one of the leading newspapers in HK. I fixed a couple of typos in what appears below, but can neither confirm nor deny the accuracy of the entire article ;-)

Scientists seek to unravel the mystery of IQ: Hong Kong supercomputers will power unique genetic study of students

Fiona Tam
Updated on Dec 04, 2010

Some of the world's fastest supercomputers are being set up in Hong Kong to address the age-old mystery of human intelligence.

The study of intelligence quotient (IQ) is being conducted by BGI Hong Kong, [formerly] known as the Beijing Genomics Institute. It will survey DNA samples from 1,000 child prodigies from China's best high schools, comparing them with samples from 1,000 children of average intelligence, searching for genetic variations.

The study will examine protein coding genes of the extremely smart children, many of whom are expected to enroll at Harvard, Yale or Cambridge. The results will be correlated with each youngster's school test scores, in hopes of learning how specific genetic variations affect intelligence.

The study, which started in 2009 in Shenzhen, is moving to a new facility in Tai Po. By the end of this month, 115 of the world's fastest sequencers - the HiSeq 2000 - will have relocated to the city. They will be able to sequence the equivalent of 1,000 human genomes a day, and soon surpass the entire sequencing output of the United States to become the world's largest sequencing centre.

The study by BGI, which receives strong financial backing from the Shenzhen and mainland governments, will be the largest-scale examination of its kind. Ethical and privacy concerns have hindered such work in America and Europe.

In fact, ethical concerns haunt this entire subject. Ever since Nazi Germany misused science to support its murderous racist and anti-Semitic theories, Western societies have been extremely sensitive about linking genetics to IQ. Nevertheless, much scientific research suggests that IQ is strongly affected by heredity, although environment, education and nutrition also play a significant role.

According to Professor Steve Hsu, who comes to the study from the University of Oregon, scientists have identified several candidate genes that may relate to IQ, although researchers are not yet sure. He said about 50 per cent of humans' IQ is substantially [heritable]. "Scientists believe there are many genes that affect IQ, but none of them has been definitively discovered so far," he said. "Although there are some candidates in published work, so far the results have not been replicated." So-called IQ genes are those that influence cognitive capabilities, including verbal and spatial abilities, perceptual speed, memory and math skills.

The BGI study, however, did not begin by focusing on suspected IQ genes nor on candidate areas. Instead, geneticists from BGI, together with researchers from Harvard, Oregon and San Diego, are surveying markers across complete sets of genomes, using a method called GWAS (Genome Wide Association Study).

The GWAS method has proved particularly useful in finding genetic variations that contribute to complex diseases such as asthma, cancer, diabetes, heart disease and mental illnesses. Researchers first obtain DNA samples from each child by rubbing a swab inside his or her mouth to collect cells. DNA is extracted from the cells and spread on tiny gene chips, which can be later read and automatically surveyed by sequencers in the laboratory.

Specialists known as bioinformaticians will then build a genetic model and calculate the differences in genetic variations between the two groups of youngsters using supercomputers. When variations of brain-related genomes are found to be significantly more frequent in smart children than average ones, these variations will be associated with intelligence. Researchers will use these variations to identify the genetic differences that determine IQ.

Hsu said: "Typical genotyping [or analysis] scans the markers of genetic variation, known as single-nucleotide polymorphism[s], or SNPs. However, scanning the SNPs only gives researchers a crude picture. BGI's sequencing capacity enables us to scan the whole genome rather than just the SNPs." Hsu, a theoretical physicist, is helping the team improve its model design and calculations.

Yin Ye, BGI's vice-president, said researchers have already made some discoveries about IQ genes, but "it's too early to make public our results". While reluctant to give further details about the experiment, he took pains to say the study was essentially focused on studying students' aptitudes and suggesting occupations that would make the best use of their capabilities.

Hsu said the genetic basis for intelligence and other characteristics or traits - known as phenotypes - was likely to be discovered in the next five or ten years.

"Even if our planned study fails," Hsu said, "it's clear on the basis of trends in cost and capacity of sequencing [that] massive GWAS involving 100,000 or 1,000,000 individuals are right around the corner."

The idea of probing the genetic basis for human intelligence came after Beijing high school student Zhao Bowen, 17, who came to BGI on a summer internship last year to work on cucumbers, solved an assignment within a few hours that scientists expected to take him weeks.

Zhao is working as a full-time researcher now, and he will study the genes of 1,000 of his best-performing schoolmates from the affiliated high school of China's prestigious Renmin University, where some of the smartest children from across the country have been sent. It's a collaboration project between the institute and the high school.

Liu Pengzhi , principal of the affiliated high school, told parents in a forum that prodigies accounted for 1 to 3 per cent of the population, and the school was working closely with BGI to develop talented children, in addition to the high school's own experimental classes for nurturing prodigies.

Wednesday, December 01, 2010

How the other half lives: quants

I was asked to write a review of Scott Patterson's book The Quants for Physics World, a UK magazine. You can read the whole thing at the link below. My review went through some British copy editing, which changed the writing style slightly :-)

Physics World: This past summer I spent the long US Independence Day weekend at a reunion with three of my undergraduate classmates. All of us went on to earn PhDs in physics, but I am the only practising physicist. The others work in finance – one at a hedge fund, the other two at major banks. They all seem to be enjoying their work, and they have obviously been very successful: our reunion took place near a famous ski resort, where one of the financiers has built a 1200 m^2 retreat complete with gym, indoor pool and wine cellar.

Even the brightest graduate students in maths and physics know that their chances of assuming a position like that of their PhD supervisors are slim. For the last 20 years the cream of the crop of physicists leaving the field has gone on to positions in finance, typically in places such as New York or London. Once there, these individuals become hedge-fund managers, derivatives traders and risk managers, to take just a few examples from my own cohort.

So what do these people do? I have always been surprised that scientists in academia are not more curious about the lives of their former peers working in the "real world". For those who are interested, Scott Patterson's The Quants does an admirable job of exploring the increasingly mathematical and technological world of high finance, and the activities of the many physicists, mathematicians and engineers who inhabit it.

Patterson writes for the Wall Street Journal, and regular readers of the newspaper will recognize him as an insightful reporter who has covered a number of important topics over the years, most recently the rise of high-frequency trading. In researching the book, Patterson had access to a Who's Who of prominent "quants", a colourful group of characters with backgrounds and personalities that will be strangely familiar to anyone who has spent time among physicists. The term "quant" is short for "quantitative" and refers to those who apply mathematical or computational methods to finance. ...

... It is a pity that although Patterson gives us a broad survey of quant finance, he devotes little space to the bigger question: are developments such as the mathematization of markets and the flow of top brains to financial activities good for society? On this matter, perhaps it is best to leave the last word to Charlie Munger, the long-time investment partner of financial guru-in-chief Warren Buffet. Writing in 2006, Munger had the following to say about the "brain drain" of top talent into finance.

"I regard the amount of brainpower going into money management as a national scandal. We have armies of people with advanced degrees in physics and math in various hedge funds and private-equity funds trying to outsmart the market. A lot of…older people…can remember when none of these people existed…At Samsung, their engineers meet at 11 p.m. Our meetings of engineers [meaning our smartest citizens] are also at 11 p.m., but they're working on pricing derivatives. I think it's crazy to have incentives that drive your most intelligent people into a very sophisticated gaming system."

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