Saturday, April 30, 2005

Temporary yuan float

This is a weird story - the value of the yuan was allowed to float up slightly from 8.276 to 8.270 to the dollar for 20 minutes on Friday. The Times article suggest it may have been due to human error, but other sources report that the unpegging was deliberate.

NYT: Traders used to seeing a flat line on their screens day after day for the value of the yuan were especially transfixed by the brief surge because it came the same day that a state-run newspaper, The China Securities Journal, ran an article on its front page that seemed to depart from previous government statements ruling out any shift in currency policy soon.

The article asserted that China's financial system and currency regime were finally ready for the yuan to rise, provided that the rise was only a few percentage points.

The People's Bank of China, the central bank, issued a public denial by midafternoon that it had received any formal instructions from the country's political authorities to push the yuan to a new level. But the brief movement of the yuan prompted some economists to say that China may have been testing its ability to manage a small fluctuation in the value of its currency, as a possible preparation for managing an eventual change in the yuan's value.

From a comment on this housing bubble blog: "BTW, I just read a news from China saying China's central bank is going to unpeg Chinese yuan for a few hours before most Chinese start taking the week-long May 1 holidays in China. Apr 30 is like the Friday after Thanksgiving in China that most traders and brokers are on vacation, so volume is usually very light and the best time to test the market."

Wednesday, April 27, 2005

PIMCO on Bretton Woods II

The "Bretton Woods II" currency arrangement, under which China, Japan and other nations are fixing their currencies at undervalued levels relative to the dollar by funding the U.S. current account deficit, will be a key topic at PIMCO's upcoming 2005 Secular Forum.

Commentary by PIMCO MD Chris Dialynas: It is interesting because the presumption that we have a semi-fixed exchange rate system is a farce because the greater the imbalance, the greater the inclination to speculate against the debtor country in favor of the large creditor countries. This suggests that there will be a lot of speculation in Chinese assets, including property, for purposes of not only the productivity of the asset or property, but to capitalize on the revaluation of the currency as well. That means this presumed stable exchange rate regime has engendered a much riskier financial environment because as the trade imbalances grow and grow, then the risk associated with speculation against the debtor country currency becomes lower and lower.

The recycling of money is in essence providing externalities in the form of a higher U.S. dollar than should otherwise be the case, lower U.S. interest rates than would otherwise be the case, much tighter credit spreads because foreign investors are such huge buyers of U.S. corporate bonds, and lower mortgage rates because they are also investing in U.S. mortgage-backed securities. And they obviously own a lot of Treasury and agency securities. So the U.S. has much lower interest rates generally. This process has led to artificially low interest rates, low inflation rates, and an overvalued currency, and it probably manifests itself in the domestic economy in much higher housing prices, so perhaps a housing bubble as well.

The system that is advertised as Bretton Woods II, a semi-fixed exchange rate stable system, by virtue of the system itself, creates greater imbalances and a much more speculative environment. That takes us to the commodity complex. The natural equilibrating mechanism for trade balance is exchange rate adjustment and under BWI, the transfer of gold from one country to another settled trade imbalances. Gold was the stable value global asset.

If you think the dollar is at some point vulnerable to a decline in purchasing power then you obviously want to purchase hard assets now because those hard assets will retain their value in global terms if they are globally traded assets like gold, diamonds, or oil, among many other commodities. This is particularly true if the yield on dollar denominated bonds is very low.

But just as importantly, if you think that this imbalance leads to the potential for more military action, then there would be a natural tendency, it would seem to me, for leaders of foreign countries to begin stockpiling assets that they might deem valuable in time of war. Just as the U.S., during an election year, refused to open the strategic oil reserve, then you would think there would be copycat countries that, if they had not already, would establish strategic oil reserves and fill them. In that event, you get precautionary demand for oil so that the oil comes out of the ground and goes right back in to the ground. The demand for oil looks very high and prices go up based upon not only commercial demand, but also actual precautionary demand and the speculative demand derived from this BWII system.

The BWII system results in speculation and instability. Importantly, the growth rates of "emerging" economies, like China, are quite high in a BWII system as are the infrastructure requirements. The transformation of growth to newly industrialized areas results in additional demand for commodities that are inputs to the infrastructure development, resulting in a structural demand for particular commodities.

Pension funds make FX bets

It seems pretty clear to me that in the medium term the dollar will likely decline against a trade-weighted basket of currencies. But, I'm not sure it's a good idea to gamble pension money using FX derivatives. Our current low-return environment is great for hedge funds and advisors - big pools of money are forced to take risk in search of return, and need help doing it.

WSJ: Pension funds traditionally have kept the bulk of their money in U.S. stocks and bonds, where they are among the markets' biggest investors. Only in recent years have they begun to invest abroad. But with bond yields low and stocks volatile, an increasing number of pension funds are turning to the currency market in hopes of boosting their funds' returns.

This interest in currency trades reflects how an aging population and ballooning health-care costs are putting pressure on pension-fund managers to find more creative ways to increase returns. The difficult environment also is compelling many large investors to consider private equity, hedge funds, real estate and other areas they once would have dismissed as inappropriate.

Consultants such as Russell Investment Group, a Tacoma, Wash., firm with $133 billion in assets under management world-wide, are among those urging on the pension funds, saying a currency program offers several unique advantages and should be part of the typical investment portfolio. Since currency wagers are made with derivatives -- financial contracts whose value is based on the performance of an underlying asset -- funds don't need to raise large amounts of money. Currency movements also have low correlations with other markets, helping to reduce a portfolio's overall risk.


"Getting a meeting with pension funds in the past was very hard when clients were getting 20% returns from stocks," says Arun Muralidhar, a managing director at FX Concepts, a New York money-management firm with about $12 billion in assets. Now, he says, the firm is in talks with about a half-dozen pension funds that are preparing to hire a currency manager.

Foreign exchange is the world's deepest and largest financial market with a daily trading volume of $1.9 trillion. But paradoxically, it can also be one of the least efficient. That is because as many as three-quarters of the participants aren't dedicated to getting the best possible price, according to Deutsche Bank. These include exporters and importers, foreign stock managers, central banks, even tourists changing money.

International fund managers, for instance, weigh a company's share price, future earnings prospects, and broader economic considerations when determining the optimal time to buy a particular stock. Normally, they are less likely to hurry up or postpone a stock purchase based on how a currency is trading. That creates an inefficiency in the foreign-exchange markets that currency managers can exploit, says Robert Stewart, a portfolio manager for the J.P. Morgan Fleming currency-management group.

The California Public Employees' Retirement System, known as Calpers, is among the pension funds already active in the currency market. Earlier this month, the largest public pension fund in the U.S. received permission from its board to increase the size and aggressiveness of its currency bets. "We are looking into that possibility," says Eric Busay, a fund manager at Calpers.

Sunday, April 24, 2005

Asian cellphone mania

Advertising via mobile (WSJ): Cellphones now are defining a generation of Asians. There's nothing geeky about calling a South Korean a "technosexual," explains Jaehang Park, a strategy executive for Korean ad agency Cheil Communications Inc. "Devices like cellphones define how trend-setting you are," he says. One-quarter of all South Koreans maintain "cyworlds," photo Web logs that can be updated using a cameraphone.

Experimenting in Asia, U.S. companies have already learned that cellphones offer access to consumers' deepest desires and concerns. In Japan, Procter & Gamble Co.'s Whisper brand of feminine-hygiene products has signed up 80,000 women to receive messages about their "happy cycle." A February message: "Your skin gets even more sensitive and dry, especially during this period. ... Try not to use new skin-care products."

Anti-Japan protests organized via text msg and email (NYT): "Chain letter" e-mail and text messages urged people to boycott Japanese products or sign online petitions opposing Japanese ascension to the United Nations Security Council. Information about protests, including marching routes, was posted online or forwarded by e-mail. Banned video footage of protest violence in Shanghai could be downloaded off the Internet.

"Text messages, instant messaging and Internet bulletin boards have been the main channels for discussing this issue," said Fang Xingdong, chairman of, a Web site for China's growing community of bloggers. "Ten years ago, this would have been unthinkable."

In Shanghai, the local police even sent out a mass text message to cellphone users the day before that city's raucous protest. "We ask people to express your patriotic passion through the right channel, following the laws and maintaining order," the message said. Some marchers saw the message as a signal to proceed, while others took it as a warning.

Saturday, April 23, 2005

Roubini parses Greenspan remarks

Nouriel Roubini's latest post dissects Greenspan's statement to the Senate Budget Committee. On the renminbi, Greenspan notes the negative effects of the peg on China's economy - mentioning sterilization costs and resource allocation distortion - and predicts a revaluation "sooner rather than later." He also distances himself from testimony in 2001 which seemed to support the Bush tax cuts. He now says (as Paul O'Neil claimed in his book) the cuts should have had built-in triggers, limiting them if large deficits resulted.

Sen. Paul S. Sarbanes (D-Md.) said he believed it was "fair to consider how your message would be taken" and that lawmakers saw Greenspan's 2001 remarks as "providing a green light" for tax cuts, which were enacted without triggers.

"I plead guilty to that," Greenspan said. "If indeed that is the way it was interpreted, I missed it. In other words, I did not intend it that way."

..."The federal budget deficit is on an unsustainable path, in which large deficits result in rising interest rates and ever-growing interest payments that augment deficits in future years," Greenspan said in his prepared testimony yesterday.

Credit boom ending?

Barron's: SPEAKING OF PICTURES that aren't very pretty, as we just were, take a gander at the two charts that adorn these scribblings. They're both lifted from Stephanie Pomboy's latest MacroMavens commentary and, frankly, they're more than a little ominous. For what they show is how dependent this quixotic economic recovery has been on IOUs.

The remorseless decline in wages as a percentage of personal income has reached an historic low of 62% (the chart to your left). Meanwhile, consumer spending as a percentage of wages continues to spiral upward (the chart to your right). In the past three years, Stephanie reckons, shop-happy consumers, cheerfully determined to live beyond their means, leaned a lot more heavily on borrowings ($675 billion of non-mortgage debt) than paychecks ($530 billion) to cover the $1.3 trillion increase in their spending.

Great while it lasts, but even the best of sprees -- and it hurts to be the bearer of sad news -- can't go on forever. And this one looks like its time is almost up. Higher interest rates, obscene gasoline prices and the rising cost of just about everything are starting to sap consumers' confidence, to say nothing of their capacity to consume. Retail sales this month, Stephanie takes somber note, have been the weakest since the last recession.

Over on the other side of the fence that separates presumed investment sophisticates from us poor civilians, risk-consciousness is suddenly the in thing. The spread in yields between junk and Treasury paper -- a handy gauge of how venturesome or apprehensive the folks who speculate in bonds are -- has begun to widen, and the flow of corporate bond issues is contracting sharply. Which Stephanie proclaims as clear proof of the dearth of liquidity in the corporate bond market.

Making things infinitely more disturbing is that the companies in the crosshairs, as she puts it, are the very creators of credit -- the likes of GM, Ford, Fannie Mae -- along with the facilitators (nice euphemism, Steph) of credit -- AIG, Ambac, MBIA, to name only a few.

That the demon debt is finally exacting its due from consumer and corporate borrower leads her to the melancholy but unsurprising conclusion that "the great credit boom is now drawing to a close." And here we were so hoping Mr. Greenspan could take his leave smiling.

Friday, April 22, 2005

JHU Talk

I'm going to be at Johns Hopkins next week, giving a talk on the null energy condition and instabilities. The slides (big PDF file, subject to change, no fair peeking if you are a JHU theorist) can be found here.

Rent-buy arbitrage

The analysis below of bay area rent-buy arbitrage is taken from Bay Area Housing Crash, where you can find much more information on the housing bubble. The author claims that recent reported sales price numbers are inflated and that prices have already started to decline in certain bay area markets.

"There are great tax advantages to owning." FALSE.

It is now much cheaper to rent a house in the San Francisco Bay Area than it is to own that same house. This is true even with the deductibility of mortgage interest figured in. It is possible to rent a good house for $1800/month. That same house would cost $600,000. Assume 6% interest ($3000 per month), $2000 closing costs, and a buyer loses $770 more per month buying than renting. Renting is a loss of course, but buying is a bigger loss.

Renting: Monthly Rent: $1,800.00

Property Tax: $400.00 ($625 per month at 1.25% before deduction, $400 lost after deduction)
Interest: $1,920.00 ($3000 per month at 6% before deduction, $1920 lost after deduction)
Other Costs: $250.00 (insurance, maintenance, etc)
Total: $2,570.00

Buyers still have to come up with the principal payment as well, just to watch it wiped out as the value of their house declines.

Remember that buyers don't deduct interest from income tax; they deduct interest from taxable income. Interest is paid in real pre-tax dollars that buyers suffered to earn. That money is really entirely gone, even if the buyer didn't pay income tax on those dollars before spending them.

Buyers do not get interest back at tax time. If a buyer gets an income tax refund, that's just because he overpaid his taxes, giving the government an interest-free loan. The rest of us are grateful.

Under current conditions, a renter would be able to live in a house for 30 years, then buy that house outright with the saved principle payments, and have an extra $277,200 of savings on top of that: ($770 x 12 x 30). The renter comes out way ahead of the owner, and this doesn't even count the huge losses the owner will suffer as housing falls year after year for the next decade or more, just as in Japan.

Another way to look at it is that except for the rich, everyone either rents a house or rents money to buy a house. To rent money is to take out a loan. A mortgage is a money-rental agreement. Owners with a mortgage seem to be renting their house from the bank, but there's an important difference. The bank takes no risk, the same as real renters take no risk. It's the owners who bear all the risk of falling house prices, and all the costs of repairs.

Thursday, April 21, 2005

Oppenheimer centenary

2004 was the 100th anniversary of J. Robert Oppenheimer's birth. See here for a partial list of recent biographies, and here for a Times review of two of them.

I can think of few figures as complex as Oppenheimer. "American Prometheus" (the title of one of the biographies) is a suitable characterization. From the Times review: "American Prometheus" is a work of voluminous scholarship and lucid insight, unifying its multifaceted portrait with a keen grasp of Oppenheimer's essential nature. What did he do upon finding himself in a Capitol Hill elevator with Senator Joseph McCarthy, the embodiment of Oppenheimer's comeuppance? "We looked at each other," the physicist told a friend, "and I winked."

"American Prometheus" sees the full implications of such a gesture: charm and bravado on the surface, Dostoyevskian darkness underneath. It traces Oppenheimer's arrogance to the kind of upbringing that would give him his own sloop at age 16 (he named it for a chemical compound) and lead one of the oral examiners of his doctoral thesis to say: "I got out of there just in time. He was beginning to ask me questions."

Many of the stories from his time at Berkeley, Caltech, Los Alamos and the IAS concern his role in the Manhattan project, or his communist sympathies and fall from grace during the McCarthy era. His contributions as the founder of what was at the time the leading school of American theoretical physics are often overlooked.

Perhaps most important was his work in the 1930's on the endpoint of stellar evolution, with his students Volkoff and Snyder at Berkeley. They explored many of the properties of black holes long before the term "black hole" was coined by Wheeler. Oppenheimer and company were interested in neutron star stability, and gave the first general-relativistic treatment of this complicated problem. In so doing, they deduced the inevitability of black hole formation for sufficiently massive progenitors. They also were the first to note that an infalling object hits the horizon after a finite proper time (in its own frame), whereas an observer orbiting the hole never actually sees the object hit the horizon. The work received amazingly little attention during Oppenheimer's life. But, had Oppenheimer lived another few decades, it might have won him a Nobel prize.

Tuesday, April 19, 2005

China labor market

So, I guess this means that a middle manager for a foreign company in Beijing or Shanghai makes 20-30 times what the average rural worker does? And I thought the US had a problem with income inequality...

Economist: CAN China—population 1.3 billion—really be running short of people? In many of the most important parts of its booming economy, the answer, increasingly, is yes. Though China has a vast pool of unskilled labour, firms in the south now complain that they cannot recruit enough cheap factory and manual workers. The market is even tighter for skilled labour. As the economy grows and moves into higher value-added work, the challenge of attracting and retaining staff is rising with the skill level, as demand outstrips supply...

Pay and benefits are soaring. A Chinese middle manager at a foreign company in Beijing or Shanghai can now command total annual cash compensation (salary plus bonus) of $27,000-$32,000, says Hewitt. Senior managers receive between $46,000 and $54,000 and top executives can expect $80,000 to $90,000 or more. While underlying inflation in China is around 2%, average annual salary increases for mid-level and senior managers are now 6-10%. Lai Kam-tong at the Hong Kong Institute of Human Resource Management says that accountants' salaries are rising by 14% a year. Jürgen Viethen, general manager for F&G China Electric, a small Spanish-owned electrical switchgear-maker, is offering key employees raises of up to 50%—and still losing them.

Saturday, April 16, 2005

US broadband penetration lags

We're last in the G8 and only 13th in the world in broadband penetration. Countries with higher population densities have a big advantage in the economics of broadband deployment, but this author suggests that we've not been aggressive enough in policy making. Recent legislative fights over whether cities should be allowed to roll out universal WiFi make me wonder whether entrenched interests (e.g., of telcos or other providers) aren't slowing down deployment. The article does a nice job of describing how Japan, which lagged terribly in the late 90's, rapidly surpassed the US.

The point about innovation being driven by small companies in markets where broadband penetration is highest is very true. Consumers react to new technologies in unpredictable ways, so proximity is key to understanding which products and services will succeed. Tech innovators here are keenly interested in what Korean and Japanese kids are doing with their 3G mobiles and home fiber optic connections.

Foreign Affairs: Once a leader in Internet innovation, the United States has fallen far behind Japan and other Asian states in deploying broadband and the latest mobile-phone technology. This lag will cost it dearly. By outdoing the United States, Japan and its neighbors are positioning themselves to be the first states to reap the benefits of the broadband era: economic growth, increased productivity, and a better quality of life.

...The large broadband-user markets of Northeast Asia will attract the innovation the United States once enjoyed. Asians will have the first crack at developing the new commercial applications, products, services, and content of the high-speed-broadband era. Although many large U.S. firms, such as Cisco, IBM, and Microsoft, are closely following developments overseas and are unlikely to be left behind, the United States' medium-sized and smaller firms, which tend to foster the most innovation, may well be.

The Japanese and the South Koreans will also be the first to enjoy the quality-of-life benefits that the high-speed-broadband era will bring. These will include not only Internet telephones and videophones, but also easy teleconferencing, practical telecommuting, remote diagnosis and medical services, interactive distance education, rich multimedia entertainment, digitally controlled home appliances, and much more.

Friday, April 15, 2005

Bay area housing bubble going strong

SJMercuryNews: The numbers say it all: Between February and March, the median price for a single-family house jumped $36,000, or 6.3 percent. Over the last 12 months, it soared $106,000, or 21 percent, hitting $605,000 in March.

That appreciation far exceeded the $74,124 that the typical Bay Area household earned last year, according to

Numbers are for existing single-family houses in the nine counties. February to March 2005, median price and percent change.

BAY AREA $605,000 +21.2%
MARIN $918,000 +22.4%
NAPA $551,000 +15.5%
SAN FRANCISCO $746,000 +14.9%
SAN MATEO $790,000 +22.9%
SONOMA $528,000 +21.9%
ALAMEDA $565,000 +20.2%
CONTRA COSTA $535,000 +28.9%
SANTA CLARA $665,000 +17.9%
SOLANO $405,000 +22.7%

Source: DataQuick

Wednesday, April 13, 2005

Test your ancestry!

Have your mtDNA or Y-chromosome DNA analyzed to determine your genetic lineage! All it takes is $99 and a swab of cells from the inside of your mouth.

One of my colleagues teaches in a department where the mantra "there is no scientific basis for race" has been repeated for a generation now. I told him I would volunteer to do the test if he would use the results to teach his students about the subject. Gee, I wonder if I am descended from Genghis Khan's line (which includes an estimated 16 million living people, mostly in Asia). (See related post here.)

The National Geographic Society, IBM, geneticist Spencer Wells, and the Waitt Family Foundation have launched the Genographic Project, a five-year effort to understand the human journey—where we came from and how we got to where we live today. This unprecedented effort will map humanity's genetic journey through the ages.

The fossil record fixes human origins in Africa, but little is known about the great journey that took Homo sapiens to the far reaches of the Earth. How did we, each of us, end up where we are? Why do we appear in such a wide array of different colors and features?

Such questions are even more amazing in light of genetic evidence that we are all related—descended from a common African ancestor who lived only 60,000 years ago.

Though eons have passed, the full story remains clearly written in our genes—if only we can read it. With your help, we can.

When DNA is passed from one generation to the next, most of it is recombined by the processes that give each of us our individuality.

But some parts of the DNA chain remain largely intact through the generations, altered only occasionally by mutations which become "genetic markers." These markers allow geneticists like Spencer Wells to trace our common evolutionary timeline back through the ages.

"The greatest history book ever written," Wells says, "is the one hidden in our DNA."

Monday, April 11, 2005

New startup

Software startup seeks summer interns and permanent employees

We are a venture-backed software startup in silicon valley, building an innovative security product. The two founders are PhDs and experienced entrepreneurs. Our previous startup successfully shipped a pioneering product (SSL VPN) and was acquired by Symantec in 2003.

CS or strong computing backgrounds preferred. Especially interested in the following skill sets (requirements for summer students are less stringent):

• Programming on a Microsoft Windows platform (NT, 2000, XP, or 2003)
• Knowledge of MFC, ATL, and Win32 programming in Visual Studio
• A background in unmanaged C and C++, with a willingness and understanding on how to work in managed C++ and C# as is needed
• The ability to administer Windows 2000, XP and 2003 (set up and debug)
• Device driver experience
• Object-oriented programming and design experience
• An understanding of the software development cycle, versioning systems, and bug management systems
• Solid communication skills
• A desire to work in the challenging and rewarding startup environment.

Compensation is competitive, including stock options.

Contact: Steve Hsu

Saturday, April 09, 2005

Super geek radio

Berkeley Groks Science Show - with Charles Lee and Frank Ling, both Caltech grads and Berkeley PhDs. Interesting interviews: Roger Penrose, Steve Wolfram, David Goodstein, Simon Singh, Steve Pinker and many others. Look for it on iPodder!

Wednesday, April 06, 2005

Theorem-proving machines

The Economist has a nice article on the status of computer-aided proofs of mathematical theorems. The Kepler problem (sphere-packing in 3 dimensions) was solved a few years back using computer programs to check the 100K cases left after analytical work (shout out to Tom Hales :-) and the article mentions a new proof of the four-color theorem.

Mathematics will likely evolve to be more like physics, with "black box" computer components in complicated proofs playing the role of experimental data. Frankly, I don't see how this is very different from the previous situation. We have always had to accept the non-zero probability that a proof might have an error or loophole in it.

R. Solovay (who retired from Berkeley and is here in Eugene now) recently found a problem with Nash's almost 50 year old proof of the embedding theorem that the community had overlooked (see note below). I may have played a small role in this as I had been reading A Beautiful Mind around the time Solovay moved to Eugene, and asked him about Nash and the embedding theorem. This may have gotten him interested in the proof...

In the end, our grip on reality (even mathematical truth) is Bayesian at best :-)

(John Nash)

Recently I was notified by an e-mail from Prof. R. M. Solovay of a fault in the last part of the published paper "The Imbedding Problem for Riemannian Manifolds" which appeared in 1956 in the Annals of mathematics. At first I didn't believe that he had really found a flaw in the arguments, thinking that he had just failed to follow the line of argument. But when I was forced to re-examine it I saw that indeed his critique of the argument was quite accurate. There was simply a gap in the logic of the attempted device for assuring the avoidance of self-intersections in the embedding of a non-compact manifold of n intrinsic dimensions in an Euclidean space of (n+1)*(n/2)*(3*n+11) dimensions.

In principle it is not very difficult to arrange for that, in the context of the means being used (as of the time of that original paper). But a rigorous argument would need to be given and it would seem that such a repair would take a different line from the scheme that was described but which was not correct.

Of course subsequent work by others has achieved results that need much less in terms of the number of dimensions for embeddings, at least for a sufficiently smooth given original Riemannian manifold for which the embedding is sought.

Enclosed here (below) is a copy of Solovay's note that drew my attention to the fault in the originally presented argument.

Monday, April 04, 2005

New paper

This paper follows up on our earlier work on the null energy condition (NEC). Imagine you've built a device which "warps" spacetime enough to create a wormhole or time machine. General theorems show that somewhere the matter in your device has to violate the NEC. In our earlier work we showed that any classical system which does so is unstable to small perturbations. In this paper, we show that semi-classicality of the device spacetime is a strong enough condition to require semi-classicality of the matter fields from which it is constructed. In other words, a device which warps space in a deterministic (nearly classical) manner is subject to the earlier results and is unstable.

We leave open the possibility of intrinsically quantum (or "fuzzy" devices) whose spacetime is strongly fluctuating. However, these might not be the most safe or realiable means of transportation! A wormhole or time machine cannot be both predictable and stable.

Semi-classical wormholes and time machines are unstable
Authors: Roman V. Buniy, Stephen D.H. Hsu

We show that Lorentzian (traversable) wormholes and time machines with semi-classical spacetimes are unstable due to their violation of the null energy condition (NEC). Semi-classicality of the energy-momentum tensor in a given quantum state (required for semi-classicality of the spacetime) implies localization of its wavefunction in phase space, leading to evolution according to the classical equations of motion. Previous results related to violation of the NEC then require that the configuration is unstable to small perturbations.

Sunday, April 03, 2005

Friedman and flattening

Tom Friedman's new book, The World Is Flat: A Brief History of the Twenty-First Century, is out soon. The Sunday Times magazine has a nice article adapted from the book. I often find Friedman a bit too breathless and exaggerated, but this excerpt is better than what I recall from his previous book on globalization, The Lexus and the Olive Tree.

[''India had no resources and no infrastructure,'' said Dinakar Singh, one of the most respected hedge-fund managers on Wall Street, whose parents earned doctoral degrees in biochemistry from the University of Delhi before emigrating to America. ''It produced people with quality and by quantity. But many of them rotted on the docks of India like vegetables. Only a relative few could get on ships and get out. Not anymore, because we built this ocean crosser, called fiber-optic cable. For decades you had to leave India to be a professional. Now you can plug into the world from India. You don't have to go to Yale and go to work for Goldman Sachs.'' India could never have afforded to pay for the bandwidth to connect brainy India with high-tech America, so American shareholders paid for it. Yes, crazy overinvestment can be good. The overinvestment in railroads turned out to be a great boon for the American economy. ''But the railroad overinvestment was confined to your own country and so, too, were the benefits,'' Singh said. In the case of the digital railroads, ''it was the foreigners who benefited.'' India got a free ride.

...Some three billion people who were out of the game walked, and often ran, onto the playing field. I am talking about the people of China, India, Russia, Eastern Europe, Latin America and Central Asia....Sure, not all three billion can collaborate and compete. In fact, for most people the world is not yet flat at all. But even if we're talking about only 10 percent, that's 300 million people -- about twice the size of the American work force. And be advised: the Indians and Chinese are not racing us to the bottom. They are racing us to the top. What China's leaders really want is that the next generation of underwear and airplane wings not just be ''made in China'' but also be ''designed in China.'' And that is where things are heading. So in 30 years we will have gone from ''sold in China'' to ''made in China'' to ''designed in China'' to ''dreamed up in China'' -- or from China as collaborator with the worldwide manufacturers on nothing to China as a low-cost, high-quality, hyperefficient collaborator with worldwide manufacturers on everything. Ditto India. Said Craig Barrett, the C.E.O. of Intel, ''You don't bring three billion people into the world economy overnight without huge consequences, especially from three societies'' -- like India, China and Russia -- ''with rich educational heritages.''

...If you want to appreciate the sort of challenge we are facing, let me share with you two conversations. One was with some of the Microsoft officials who were involved in setting up Microsoft's research center in Beijing, Microsoft Research Asia, which opened in 1998 -- after Microsoft sent teams to Chinese universities to administer I.Q. tests in order to recruit the best brains from China's 1.3 billion people. Out of the 2,000 top Chinese engineering and science students tested, Microsoft hired 20. They have a saying at Microsoft about their Asia center, which captures the intensity of competition it takes to win a job there and explains why it is already the most productive research team at Microsoft: ''Remember, in China, when you are one in a million, there are 1,300 other people just like you.''

...Compared with the young, energetic Indians and Chinese, too many Americans have gotten too lazy. As David Rothkopf, a former official in the Clinton Commerce Department, puts it, ''The real entitlement we need to get rid of is our sense of entitlement.'' Second, we have a serious numbers gap building. We are not producing enough engineers and scientists. We used to make up for that by importing them from India and China, but in a flat world, where people can now stay home and compete with us, and in a post-9/11 world, where we are insanely keeping out many of the first-round intellectual draft choices in the world for exaggerated security reasons, we can no longer cover the gap. That's a key reason companies are looking abroad. The numbers are not here. And finally we are developing an education gap. Here is the dirty little secret that no C.E.O. wants to tell you: they are not just outsourcing to save on salary. They are doing it because they can often get better-skilled and more productive people than their American workers.

These are some of the reasons that Bill Gates, the Microsoft chairman, warned the governors' conference in a Feb. 26 speech that American high-school education is ''obsolete.'' As Gates put it: ''When I compare our high schools to what I see when I'm traveling abroad, I am terrified for our work force of tomorrow. In math and science, our fourth graders are among the top students in the world. By eighth grade, they're in the middle of the pack. By 12th grade, U.S. students are scoring near the bottom of all industrialized nations. . . . The percentage of a population with a college degree is important, but so are sheer numbers. In 2001, India graduated almost a million more students from college than the United States did. China graduates twice as many students with bachelor's degrees as the U.S., and they have six times as many graduates majoring in engineering. In the international competition to have the biggest and best supply of knowledge workers, America is falling behind.'']

Friday, April 01, 2005

Exorbitant CEO compensation

Lucian Bebchuk of Harvard Law School and Yaniv Grinstein of Cornell University's Johnson School of Management found that top five executives at public companies received $92 billion in total compensation from 2001 to 2003, amounting to 10.3 percent of their firms' total net income. The ratio was more than double the 4.8 percent from 1993 to 1995, the authors said. (Houston Chronicle.)

Oded Shenkar - The Chinese Century

Dr. Moira Gunn speaks with professor Oded Shenkar, Ford Motor Company Chair, Global Business Management, Ohio State University, and the author of, "The Chinese Century -- The Rising Chinese Economy and its Impact on the Global Economy, The Balance of Power and Your Job." (Streaming in MP3 and Windows Media.)

Shenkar points out that before the US surpassed England to become the world's largest economy (150 years ago), the British regarded Americans as cheap labor, and felt confident about their superior ability to innovate :-) He also mentions that the number of science and technology PhDs produced in Asia now surpasses the number produced here. (Furthermore, half of US PhD recipients are foreign nationals.)

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