Why you should not bother to switch the envelope

You are presented with two envelopes, and are told that one contains twice as much money as the other. You are to choose one envelope and earn the money in it. You pick one envelope, and upon opening it, find that it contains y dollars. You have the option to keep that envelope, or to switch to the other envelope. Should you switch?

Here is the paradox: there is a 1/2 chance that the other envelope contains 2y dollars, and a 1/2 chance that it contains y/2. If you switch the envelope, your expected earning is 1/2 × 2y + 1/2 × y/2 = 1.25y, which is greater than y—your expected earning should you choose to stay with the current envelope. To earn more money, you should, therefore, switch.

It does not make sense, does it? Intuitively it should not matter whether you switch or not, because the envelope that you end up with is equally likely to be the one with more money or the one with less. So what is the logic flaw in the paradoxical argument above?

Let's say that one envelope contains x dollars and the other 2x dollars. When you pick one envelope, you have an equal chance of picking either one, i.e., P(y is x) = P(y is 2x) = 1/2. Should you choose not to switch, your expected earning is P(y is x) y(y is x) + P(y is 2x) y(y is 2x) = 1/2 × x + 1/2 × 2x = 1.5x. Here is an important subtlety: I've written y(y is ...) to denote the revealed amount y upon opening the envelope, in the two different events of y being either 2x or x; that amount is not the same for the two events! In other words, you cannot write the expected earning as P(y is x) y + P(y is 2x) y = y, because y is different in the two different events of "y is x" and "y is 2x"!

Should you switch the envelope, your expected earning is P(y is x) 2 × y(y is x) + P(y is 2x) 1/2 × y(y is 2x) = 1/2 × 2x + 1/2 × x = 1.5x, which is exactly the same as that should you keep your original choice.

The paradox is thus resolved by defining the right set of events ("y is x" and "y is 2x") and realizing that the revealed amount y is not a constant for these different events, but a function whose value varies between the events: y(y is x) = x, while y(y is 2x) = 2x.

Wait a minute, some may say. If you are told that the other envelope has equal probability of containing 2y or y/2 dollars, after you open the first envelope and find within it y dollars, you should obviously switch. So what is the difference between this setup and the original one?

Well, the two setups are quite different. To clarify their difference, it is helpful to consider how the second setup can be correctly implemented. A simple way is to begin with an empty envelope, and have another person put in it either 2y or y/2 with equal probability after you open the first envelope. No matter how it is implemented, the second setup requires making changes to the envelopes after the first envelope is opened, and the change depends on the amount in the opened envelope. So you will be playing a different game than the original one: in the original setup, the two envelopes are prepared beforehand and are not adjusted after your first pick.

The difference between the second and the original setup thus reveals the true fallacy of the paradox: it confuses the expectation of a two-step procedure with that of its second step alone. The two steps are: 1) pick one envelope out of the two, find out the amount within, 2) decide whether to keep it or switch to the other. Your expected earning depends on your action in the first step as well as on the second.

After opening the first envelope and finding y dollars in it, there are two possibilities for the initial set-up of envelopes: {y, y/2} and {2y, y}, and they are equally probable: P({y, y/2}) = P({2y,y}) = p. The expected earning, should you decide to switch on the second step, is

   P({y,y/2})[P(1st is y|{y,y/2}) y/2 + P(1st is y/2)|{y,y/2}) y] 
+ P({2y,y})[P(1st is y|{2y,y}) 2y + P(1st is 2y)|{2y,y}) y] = 2.25 p y

The expected earning of not switching on the second step is

   P({y,y/2})[P(1st is y|{y,y/2}) y + P(1st is y/2)|{y,y/2}) y/2] 
+ P({2y,y})[P(1st is y|{2y,y}) y + P(1st is 2y)|{2y,y}) 2y] = 2.25 p y

Again, there is no difference either you keep your pick or switch.

There is actually another subtlety. In the above analysis, I should have written P(y is x|y) and P(y is 2x|y) to denote the conditional probabilities that the picked envelope contains x or 2x, given that the revealed amount is y. I have taken P(y is ...|y) = P(y is ...), with the assumption that seeing what is in the envelope does not tell you any information on whether it is x or 2x. This is not necessarily true when you have additional information available. For example, if you know that neither envelope contains more than 1 million dollars, and your opened envelope contains over half a million dollars, you should definitely not switch. On the other hand, if your opened envelope contains 5 cents, and realistically you know that there is no way for the other envelope to have 2.5 cents (physically impossible), you should definitely switch since you now know for sure that the other envelope has 10 cents in it.

Three Inches of Heaven

Stopping here, dare not to go on,
Stop the sorrows behind the curtains.
The farewell that you've handwritten on the next page,
Is beyond my power to refuse.
We've taken this road in much haste,
Holding onto false desires.
'Tis too late, 'tis beyond our patience,
To appreciate all that we've left behind,
Magnolia's scent cannot seal our wounds.
Look no more, the sun shine through the clouds in the sky,
Seek no more, the heaven of our rendezvous.
Lament no more, what you called fortune's constant reversals,
The three inches of sun shine that we cannot borrow.
Heaven is where our love has dominion.

三寸天堂

停在这里不敢走下去，让悲伤无法上演。
下一页你亲手写上的离别，由不得我拒绝。
这条路我们走得太匆忙，拥抱着并不真实的欲望。
来不及等不及回头欣赏，木兰香遮不住伤。
不再看，天上太阳透过云彩的光。
不再找，约定了的天堂。
不再叹，你说过的人间世事无常，借不到的三寸日光。
那天堂是我爱过你的地方。

The Modern Experience

The most joyful thing in life is to deal with people who know what they are doing. Take, for example, the dinner tonight at The Modern restaurant. The chef clearly knew what he was doing, for the food was impeccable. But the girl at the coat-check left the deepest impression. She was cuter than the average coat-check girl, with an engaging smile, and she definitely knew what she was doing. The six of us arrived in the evening after a day of heavy snow, and we each checked in our coat. I had a stack of paper with me, which I forgot to check in with my coat. We were seated, upon which I realized that my papers were an incongruous addition to the table. So I returned to the coat check, and asked the girl to keep my papers with our coats.

A fabulous meal later, I got my coat back. Neatly tucked in my coat pocket - my papers. The girl knew which coat was mine! The final score on The Modern - food: 9, coat check girl: 10.

Making sphinx work with postgresql

On my MacPro, PostgreSQL is installed in /Library/PostgreSQL/8.4/. To install sphinx and have it work with PostgreSQL, I need to configure it in the following way:

./configure --with-mysql --with-prefix=/usr/local/sphinx --with-pgsql --with-pgsql-includes=/Library/PostgreSQL/8.4/include/ --with-pgsql-libs=/Library/PostgreSQL/8.4/lib/

Getting postgis to work with django (and sphinx)

The django-sphinx package does not recognize the postgis backend; one needs to modify the /path/to/djangosphinx/utils/config.py and reinstall it to make the two work together. Add the following to _get_database_engine() in the config.py file:

def _get_database_engine():
...
elif 'postgis' in settings.DATABASES['default']['ENGINE']:
return 'pgsql'

If you are creating a database as the default superuser postgres but you will be connecting to the database as a different user (say chineseblade), it is necessary to grant the privileges to the user. Sadly, if you use template_postgis as a template in creating the database, you will need to grant accesses to the tables geometry_columns and spatial_ref_sys individually, in addition to granting privileges on the database itself. The procedure is

Log on to the database template_postgis as the superuser postgres, and issue commands:

grant select on table spatial_ref_sys to chineseblade;
grant all on table geometry_columns to chineseblade;

Log out, then log on the master database postgres, and create the database using the template:

create database mydb with template=template_postgis;
grant all privileges on database mydb to chineseblade;

Now in the settings.py in your project, set the database engine to 'django.contrib.gis.db.backends.postgis'. You are ready to go!

Death of a dreamer

What happens when a man dies in his own dream? Does he wake up or does he start another dream? It is one of the intriguing questions posed by the movie Inception. I have come close to dying in my own dreams, but I have always managed a narrow escape. This makes me think that death to oneself in a dream is something that simply does not happen. Our survival instinct may have diffused into our subconscious so that even in a dream, we protect ourselves from the ultimate self-destruction.

If you have experienced death in your dreams, please leave a comment here.

Obama Care, Not Even Wrong

The health care bill passed on Sunday, March 21st, 2010. A historic moment. It will be interesting to observe its consequences in the next decade, a potential gold mine for economists.

On the following Monday I had a lunch conversation with a colleague, and the issue of health care was briefly brought up. My colleague said that he just could not understand why anybody could have opposed the bill, why anybody would think that universal health care could be a bad thing. I was quite surprise by that statement, coming from a highly educated intellectual. Because nobody thought that universal health care was a bad thing, in the sense that it was morally unjustified. People opposed it for economical reasons. People opposed it because they had not been convinced that the benefit to the nation would outweigh the economic cost. My colleague's comment just made me realize that some supporters of the health care bill had only been considering the bill on moral righteousness, not on economical feasibility.

When I pass by a homeless person on the street, I also feel the moral obligation to help. Everyone should be entitled to a roof over the head, as much as everyone should be entitled to care in sickness. But there is no legislation for universal housing.

New York City has aggressively cut its subway services. Now I often wait twice as long for a train as before. No one could have thought that cutting subway service was a good thing. But sometimes it is the fiscally responsible thing to do. Policy making is not so much about doing the morally right as about setting the right priorities, and investing the resource where it will benefit the society the most.

There are many things that should be deemed universal rights, the "good things", but in reality are not available to everyone, for the simple reason that there is not enough of it to share. It seems strange to me that some legislators are arguing the health care bill on the moral ground: "If you think it is right, you gotta help us finish the fight." That seems like sports trash talk, not a cool headed argument. The morally correct is not always economically right.

If anything, better education for everyone makes more sense than health care for everyone. After all, people don't fall sick often, and most minor ailments heal by themselves. Poor education, on the other hand, hurts a person for life, day in, day out. A better education is not only essential to maintain United States' competitive edge, but it will also better equip the Americans to evaluate the legislative bills more rationally, instead of being swayed by politicians' hot-headed rhetorics.

I kept wondering: if universal health care was such an obviously good thing, why was Massachusetts the only state in the nation that independently enacted it? Why did all the other states choose not to follow suit on their own and enact their own universal health care for their state citizens?

Even if we limit the debate entirely to the moral ground, I cannot fully justify universal health care, since it is not truly universal health care, but only health care for AMERICANS! Majority of the world's population live in poverty and do not have access to many basic life's needs. I personally detest any entitlement from a privileged birth, even though I accept it as a fact of life. But please do not use it as the basis of a moral argument. It is plain hypocrisy!

Obama called the passing of the bill "what change looks like". I am very disappointed. What Obama promised on his campaign was bipartisan politics. What I expected to see was a pragmatic approach to tackling the nation's most urgent problems, not the old ideological bigotry. The health care bill was passed without a single Republican vote. It was passed not because it was resoundingly convincing to the majority, but through insidious political manouvres that would surely anger its opponents and further divide this nation. If this is what change looks like, it is not the kind that I can believe in.

Cheaper expensive

As I strolled down the Madison Avenue, a sense of indignation assailed me on full scale. The display of excesses in the row of boutiques like La Perla, Oliver Peoples, and Breguet struck me as a manifestation of social inequality. Is there any justice that a bra, a pair of sunglasses, or a watch should cost so much that they are beyond the reach of ordinary hardworking Americans? Why is there not a legislative motion to rein in the cost of luxury goods, to make them universally accessible to all citizens of this wealthiest nation in the world?

A person with even the faintest turn of mind in economics, like me, can predict what such price restriction would do. There would be no more La Perla bras, no more Oliver Peoples sunglasses, and no more Breguet watches. So far as we want to keep luxury merchandise around, there is no way to drive down their prices, for the simple reason that price is not the paramount factor in the purchase of luxury goods. Luxury goods compete in other dimensions: quality, design, and brand recognition. The rich buy what they desire, not what is cheap.

For the same reason it will be all but impossible to rein in the cost of healthcare without sacrificing the quality of care. When we go see doctors, the cost of treatment is seldom on the top of our mind. Money is no good to anyone who is too sick to enjoy spending it. There is no financial incentive for the doctors not to prescribe the best - and often the most expensive - treatment, and there is little financial incentive for the patients to turn down a costly but presumably efficacious prescription.  Healthcare is analogous to luxury goods in that the providers compete not in price but in the quality and effectiveness of care. This may sound heartless - how can something essential such as physical well-being be compared to a Gucci coat or a Hugo Boss gown! But economics is a cold-blooded reptile that knows only incentives and no morals. So long as there is no incentive from either party to control the cost at the consumption end of healthcare, i.e., when the patient sees the doctor, driving down the cost will remain political hot air.

The only check on medical cost comes from the insurance companies, which employ an army of medical consultants to review the necessity of the prescribed treatments and deny the ones that are deemed wasteful. This practice, unfortunately and perhaps rightfully, is often vilified in the public media; denial of care is invariably described as an example of corporate greed of the health insurance industry. 

The only existing mechanisms to make patients more cost conscious are the deductibles and the annual ceiling in coverage. By making the patient share part of the cost for each treatment, the insurance companies quite effectively prevent wanton visits to the clinic and abuse of the medical insurance. With a spending limit each year, the patient is more likely to reject unconscionably expensive treatment, in order to save for another rainy day. Yet, effective as these measures are in fighting insurance fraud, they do little in controlling the average cost.

Last summer I had a horse riding accident, and I was rushed to the ER in a nearby hospital, in the affluent town of Huntington. In retrospect, I sustained only a minor injury: a horse kicked me just below my abdomen and to the left of my groin - the kick landed squarely where my cervical bone was the hardest and, even though a nail from the horseshoe penetrated three layers of clothing and cut a deep wound in the flesh, it did not reach the bone. I remained lucid throughout and felt no discomfort in my internal organs. Nevertheless, when the doctors prescribed two CAT scans and one X-ray, just to ensure that there was no internal trauma, I was in no position to refuse. Sure it did not feel like that I really needed them, but maybe the pain in the cut wound was obscuring signs of hidden internal injury. Was it not better to be safe than sorry? Who was I to say what diagnostics and treatments were rightfully called for? That was the doctors' job. 

The total bill came close to $30000, of which I had to pay a deductible of $450. I did not learn about the amount of the deductible during my ER visit, and had I known about this sizable deductible, most likely I would still not have said no to any of the prescribed procedures. It simply would not be worth saving $450 to risk permanent organ damage, or in the worst scenario, my life.

I too support the call to rein in the medical cost; I am simply skeptical of the proposals stemming from moral arguments. Conscience is never as effective in improving the world as sensible economic policies. The only solution to reduce the medical cost lies in instituting policies that will place economic incentives for either the doctors or the patients, or both, to be more price sensitive, right where and when the doctors treat the patients. I suspect that it will be the private sector who can do it better than the government. Sadly, whatever measure there is and will be, it is likely to be branded as the most evil of all greed: placing money in front of human lives.

Dogs as pet and meat

From Roger Cohen's Op-Ed in New York Times, Dog Days in China:

Another noted a local saying: "when the dog meat is being simmered, even the gods become dizzy with hunger."

Growing up in China, I ate a lot of dog meat. It is more flavorful than lamb, a bit chewier, and quite delicious. In New York, my wife and I had a Cocker Spaniel, Tom. When it passed away several years ago, we buried it in our backyard instead of making it a stew. If today I travel to China and eat in a Chinese restaurant that legally serves dog meat, I will order it. There is no evolutionary reason not to. Tom will not know, or care.

I suspect that "the gods" - plural in the quote from New York Times - refer not to the Christian God, but to numerous Chinese deities. There are plenty of Chinese folklore in which a dog becomes a meal for its palindromic counterpart.

I love dogs very much, both as pets and as meat. It depends on whether they are sitting by my table, or on it.

The Pursuit of Happiness

The following immortal words of The Declaration of Independence are in peril of misinterpretation:

... that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty, and the pursuit of Happiness.

Note that it is the pursuit of Happiness - not Happiness itself - that is among the unalienable Rights. The Obama administration and the current Democratic Party seem to leave out that crucial word "pursuit", and they kowtow to Americans' sense of entitlement. Forgotten are J.F.K.'s words "Ask not what your country can do for you - ask what you can do for your country." Americans now want their happiness handed to them on a plate.

It is often asserted that the citizens of the welfare states, such as the Scandinavian countries, are happier, and that Americans are among the less happy in the world. The surveys may say so, but the immigration trends seem to point to the opposite - I personally know quite a few friends who came to the States from the Scandinavian nations. Do immigrants come to the United States in search of misery? That seems to violate the basic human instinct.

Some Americans will always be happier than others; that disparity will remain ubiquitous in this world. But the strength of the United States lies in its social mobility. Nobody is limited by his or her circumstance of birth; everybody is truly blessed with the equal and unalienable right: the pursuit of happiness.

Math in Tax

I just had my taxes done. As I reviewed my tax returns, I noticed the following description on how to figure the limit on itemized deductions (http://www.irs.gov/publications/p17/ch29.html):

If your itemized deductions are subject to the limit, the total of all your itemized deductions is reduced by the smaller of the following reduced by two-thirds:

• 80% of your itemized deductions that are affected by the limit. See Which Itemized Deductions Are Limited , earlier, or

• 3% of the amount by which your AGI exceeds $166,800 ($83,400 if married filing separately).

That is a mouthful, and the rule seems contrived! Who stipulated it? The numbers seem to come out of the blue without rationale. To a scientist, it borders on the absurd. It is analogous to defining the speed of light by saying that light travels at the speed such that in a minute it covers the distance of one billion times the height of the White House on the north side. Anybody care to point me to the origin of this rule?

To assist the Americans to figure their itemized deductions, the IRS publication includes a worksheet that breaks down the calculations step-by-step. Here are lines 9 to 12:

9.	Enter the smaller of line 4 or line 8					9.	2,784
10.	Divide line 9 by 1.5					10.	1,856
11.	Subtract line 10 from line 9					11.	928
12.	Total itemized deductions. Subtract line 11 from line 1. Enter the result here and on Schedule A, line 29					12.	141,212

Do you see that line 10 is completely superfluous? Line 11 really is simply line 9 divided by 3, and line 10 does not seem to be used anywhere else in the tax return. Is it simply an opaque layer to conceal the absurdity and arbitrariness in the tax code?

Here is how to figure the limit on itemized deductions, in layman's language, but for the arithmetically more adept:

If your itemized deductions are subject to the limit, the total of all your itemized deductions is reduced by the smaller of the following:

1. 4/15 of your itemized deductions that are affected by the limit. See Which Itemized Deductions Are Limited , earlier, or
   
2. 1% of the amount by which your adjusted gross income (AGI) exceeds $166,800 ($83,400 if married filing separately).

More concisely, if the total of your itemized deductions is smaller than 3/80, or 3.75%, of the amount by which your AGI exceeds $166800, your eligible deduction will be limited to (1 - 4/15 ) = 11/15 ~ 73.3% of your total deductions; otherwise (if you manage to list a lot of itemized deductions compared to your AGI), your eligible deductions will be the total deduction reduced by 1/100 (AGI - $166800), and since that reduction is a fixed amount, there lies your opportunity of tax evasion.

Turandot

Unknowingly we are all in pursuit of Turandot, the cold, vengeful princess of Peking who confronts her suitors with her three riddles. Answer the riddles correctly, you will enjoy the conquest of the heavenly beauty of Turandot, and become the king of the vast land in the East; fail them, you will forfeit your life and have your head chopped off.

Is it worth it, to have that singular obsession, the pursuit of which makes us oblivious to all other matters in life? Is it wise to risk it all, to climb the steep and snowy mountain, in search of the legendary snow lotus, when there are so many beautiful flowers just by your feet?

Greatness is invariably born out of foolishness, a blissful state of ignorance in statistics. How much less we would have achieved if we could see into the future! Foolishness abounds; greatness, by definition, is rare. Many a prince had lost his head, literally, to the seductive beauty of Turandot, before Calaf, in a streak of good fortune, solved all three riddles, and eventually won the princess's heart. Deaf to the good advice of his father Timur, deaf to the imploring of the slave girl Liu, who was secretly in love with him, deaf to the wise words of Ping, Pang and Pong, who told him that there were a thousand faces and a thousand legs awaiting him if only he would forget Turandot and leave Peking, and deaf to the chorused dissuasion of the crowd, Calaf insisted on taking the test. A madman indeed. For him, death is preferable to the torment of a life consumed by unrequited passion.

All failures sum up to a number in statistics; success stands out as a singular event. While the severed heads of the princes before him rotted on the pikes on the streets of Peking, Calaf embraced a Turandot transformed by love. She declared to the king that she had learnt the name of Calaf, and "It is love!".

Love may there be, but surely there is a lot of luck.

Destiny on the table

My friend's son turned one today. There was a big party. After the cakes were cut and served to the guests, a few objects were placed on a low coffee table: a pen, symbolizing scholarship; a drumstick, foretelling the life of a musician; two crayons, pointing to artistic creativity; a pink plastic ribbon, embodying longevity; a $20 bill, foreshadowing a career in finance; and a calculator, auguring a career in science and engineering. The one-year old was going to pick one of these objects on his own, which would reveal his future.

The son's name is Haydn, and my friend named his dog Mozart, so there was a clear expectation from the parents. Lo and behold, Haydn, donning traditional Korean costumes, reached for the drumstick. But then something funny happened. He stopped 3 inches short, hand suspended in mid air. He was thinking, and he started inspecting other objects. Then he noticed the pen - a Mont Blanc, and without further hesitation he grasped it. Scholar he would be! Everyone in the room broke into applause. Then Haydn also took the crayons. A scholar with artistic creativity, it could not have been better.

With an analytical turn of mind, I could not help thinking about the one-year-old's choice. First, he went for the drumstick; but instead, he chose the pen and the crayons. All these objects are long cylinders, with the Mont Blanc pen being the most well-crafted (and also by far the most expensive). Perhaps all toddlers have a innate affinity for cylindrincally shaped objects, but prefer the ones that they can easily hold in their tiny hands.

Reenact a novel on Facebook

Here is a silly but potentially fun game to play on Facebook. Take your favorite novel, say, War and Peace, and for each character, Pierre Bezukhov, Natasia Rostova, etc., register a Facebook page. Next, connect the characters in friendship as they do so in the novel. As you read the novel, each day you will update each character's page with things that happen to the character. Write statements in first-person, and write them in the protagonists' own tones. Record not only the events in the protagonists' lives, but also the thoughts that may go through their minds, and the emotions that they experience - use your own imagination here to express your personal impressions. By the time you finish reading the novel, you will have reenacted the novel in the cyberspace. Won't this be fun! Better yet, it will make you pay more attention to the details in the novel, thus appreciating it better.

If you have a reading group, each member in the group can play a different character. Such a game surely will enhance the reading experience, and give you something extra to discuss over cheese and wine.

Friendship, one bite at a time

In the movie Fightclub, Norton's nameless character coined the phrase single-serving friends - strangers who share a few hours of flight time, chat, and then part their ways. On Facebook, friends are like bite-sized snacks - their frequent posts and comments alleviate the sense of separation but never satiate the craving for real connection. Just like too much snack can ruin the appetite for a real meal, the deluge of Facebook friendships, I fear, might get in the way of developing more full-fledged friendship. We take a glimpse into our friends' lives through their Facebook posts, confuse them with real conversations, and be content with an illusion of company. 

In this new era of Facebook, friendship needs a re-definition. According to Facebook, my friend Coco has 1278 friends and counting, and George recently announced that his friend count just entered 4 digit realm as well. When one's got that many friends, each friendship cannot but be diluted down. As an old Chinese saying goes: a virtuous friendship is thin but pure like water. Are all Facebook friendships not only virtual but also virtuous?

One psyche that draws us to Facebook, I suspect, is curiosity, a social voyeurism out of boredom. We are born to peek into others' lives, and now Facebook seemingly offers a way to peek into others' minds (the form on Facebook asks "What is on your mind?"). A thought, once posted, is no longer exclusively owned but is shared among all who read it. Does this allow us to vicariously live our friends' lives? When a friend posts sad feelings, does it inflict sadness among all who view the post? To what extent will the great connectivity synchronize our emotions?

On Facebook, one promotes to friends who in real life are but acquaintances. It is convenient and it costs nothing. Friendship can be deleted - a click on a button and the connection is removed; no awkward social situation is involved. One can also delete one's posts; is it equivalent to saying "Oh, sorry, I take it back!" in a real conversation?

A Nobel SurPrize

In debating whether President Obama deserves the Nobel Peace Prize after only 9 months as the president of United States, it behooves a re-reading of Alfred Nobel's original will:

one part to the person who shall have made the most important discovery or invention within the field of physics; one part to the person who shall have made the most important chemical discovery or improvement; one part to the person who shall have made the most important discovery within the domain of physiology or medicine; one part to the person who shall have produced in the field of literature the most outstanding work of an idealistic tendency; and one part to the person who shall have done the most or the best work for fraternity among nations, for the abolition or reduction of standing armies and for the holding and promotion of peace congresses.

There is an apparent difference between the intended recipients of the Peace Prize and those of the other disciplines. In chemistry, physics, medicine, and literature, the prize should go to researchers or writers who have produced the most significant result - discoveries, inventions, or a body of literature that have transformed the scientific, technological, or cultural landscape. Notably, these prizes award impact, not effort or intention. Even though success, as Edison put it, is ten percent inspiration and ninety percent perspiration, sometimes chance happens to all. Kary Mullis won 1993 Nobel Prize in chemistry not for any heroic effort, but for his stroke-of-genius invention of polymerase chain reaction. With few exceptions, Nobel Prizes in these disciplines have rarely been given to anyone for simply tireless work - too many scientists and writers toil for a lifetime without any recognition. In short, award for quality, not quantity.

The Peace Prize is singled out because it can be bestowed upon a person who has "done the most or the best work". Now the door is open for effort, regardless of result. In the past, the Nobel Peace Prize has been repeatedly awarded for intentions and labor, even when such intentions and labor have not paid quantifiable dividend of a more peaceful or sustainable world.

Unlike the other Nobel Prizes, which are established to encourage individuals in the pursuit of science and literature, thus more immune to any mutable agenda of the committee itself, the Nobel Peace Prize takes it upon itself to promote peace in the world. The Prize committee therefore has its own political agenda. The main purpose of the award is not to recognize any individual's effort or accomplishment, but to recognize and support a cause, a policy or an action that the committee deems to be in the correct direction. It is not an award for the past, but for the present and the future. The award to Obama is not a nod to what he has achieved, but to what he is doing. In other words, the committee is making a statement that had they been elected the president of the United States, they would be instituting the same international order as Obama; they are also telling the world, be vigilant of this new course of the United States, and make sure that the Obama administration never strays from it. The award is a means for the Prize Committee to insert its own agenda into world politics.

Unfortunately, good intentions do not equal good outcomes. As the saying goes, the road to hell is paved with good intentions. (This is probably best illustrated by the predecessor of Obama.) A world without nuclear weapons may not be a more peaceful world, just one less likely to face total annihilation. The impact of policies can only be tested by time. But again, the committee of the Nobel Peace Prize is not there to assess the impact using scientific measurements, it is there to ensure that the United States, and the rest of the world, commit to the policies that the committee approves of out of their own noble intentions and gut's feelings. After all, in the long run, we are all dead; but in the next 3 years, we want to live the way that feels right.

If the Nobel Peace Prize were to be awarded for impact instead of intention, if it were to be given to people whose work have fundamentally improved fraternity among nations and different people, I would like to nominate Timothy Berners-Lee, for the invention of the internet, or Larry Page and Sergey Brin, the founders of Google. Nothing has done more to spread democracy, to combat poverty, to defeat dictators, to foster fraternity across national borders, and to carry prosperity from corner to corner in this world, than the freedom of information and instant communication brought about by the internet. If there were to be a number assigned to the impact of the internet on world peace, it would have to be googol.

The Making of a Great Scientist

When I first got into science, I thought that it was about coming up with brilliant and evolutionary ideas and the rest would come together by itself. After ten years in research, however, while being by no means a great scientist, I did learn a few things about the making of one, which I would like to share with you. It's an immodest thing to do. But anonymous modesty never serves anyone. So here I go.

First of all, if you have not read Richard Hamming's lecture, "You and Your Research", read it now. If you haven't reevaluate your research after reading it, read it again. Hamming's lecture should really be writings on the wall for all aspiring scientists, for it shows us the most important step to great research: how to pick the great problems to work on. Avoid mediocrity.

But picking the right problem is just the first step. The really great scientists are also great problem solvers. Rome is not built in one day. Great science does not happen by itself even if you have a great idea. There is only subtle difference between a genius and a mad person. That difference is the methodical implementation of one's ideas.

Once you have an idea to solve a great problem, you set out to see if it is right. You carry out an experiment. If you are really onto something big, often you will need to design a new experiment that nobody has done before, you will build some new apparatuses, write some new computer programs, collect some hard-to-collect data. (Incidentally, having to do something difficult and unusual also hints that you may be onto something significant.) These new elements bring in extra uncertainty. The experiments may at first disagree with your hypothesis. You have to determine whether your hypothesis is wrong or your experiment has flaws.

The ability to verify the integrity of your experiment is the paramount skill you need to have as a great scientist. You have to be able to design experiments where you know the outcome to test your new apparatus, devise simple models with analytical results to test your computer program.

Once your experiment agrees with your hypothesis, the real test of greatness begins. You must overcome the initial excitement, and with a cool head, consider if there is an alternative hypothesis that also agrees with your experiment. How can you design additional experiment to distinguish between different hypotheses? Don't draw conclusions too quickly.

Facebook prize

Netflix just awarded a cool million to a 7-member team who managed to devise algorithms that improved the prediction of user's ratings of movies by 10% compared to Netflix's own Cinematch algorithm, the endgame of a 4-year long contest (see NYTimes).

Isn't it time that Facebook sets up a contest of its own? With its database of human connections, Facebook can challenge the machine learning community to predict friendship: reveal 90% of each user's friends, and have the algorithm predict the rest 10%. Another challenge is to reveal each user's friends up to a certain date, and have the algorithm predict new friendships that the user forms afterwards. May the most accurate algorithm prevail.

Online dating services can certainly use such an algorithm. Who else? Insurance companies? Banks? Salespeople? How much can you learn about a person from the friends he or she keeps?

Mobile human computing

I am a big fan of Luis von Ahn's work on human computing. The idea of human computing is to harness the idle human brain power to perform computational tasks that so far have eluded the computers, such as image labeling (see google's image labeler) and recognition of old text (check out reCaptcha). The clever part of von Ahn's approach is to engage the human brain through an entertaining game or as a by-product of other necessary tasks.

I believe that this approach can be extended to the mobile phone platform. With smart phones like the iPhone, the location and time of the carrier are known, and these information should be valuable for designing location- and time-specific computational tasks. Another advantage of using smart phones as a platform for human computing is that these phones are almost always accessible at idle times - my colleagues invariably play on their iPhones when the meetings get boring. 

What can be accomplished using smart phones and idle human time? I have not come up with a specific application. But here are some general, and obvious, thoughts. Each human should be presented a simple task, which should not require expert knowledge or special skill, and should be fun to perform. The task should be easy for normal humans but difficult for even the most advanced computers, such as to observe and describe one's surroundings, or to identify a person. The outcome of all these tasks should then be combined in a way to solve a complicated problem. In order to take full advantage of the mobility of smart phones, the problem that we try to solve should ideally involve the locations and times at which the carriers perform their tasks.

Ideas?

First time pheasantry

The first bird got away. It flew away so fast that before either Yang or I opened the safety on our guns, it had crossed the grassfield and safely alighted in the woods far beyond the reach of any 12-gauge shotgun. We followed its flight path with our eyes. It was a beautiful male bird with a long tail and a dash of red on its head. We were relieved that we did not have to kill so early in the hunt. But the two dogs were disappointed.

The pointing dog was responsible for the escape of the first bird. Upon smelling the scent of the bird, the pointer should have frozen and have pointed its nose at the bird's hiding place. Instead, it came too close to the bird and flushed it out before we could ready our guns. More experienced hunters could have responded in time. But we could not raise our guns that fast yet.

Don, our guide, with a Jack Nicholson semblance and a loose lip for curse words, told us to be more ready the next time. We walked on, in wet, knee-high grass which I feared might harbor venomous snakes or ankle-breaking pits. The pointer ran around excitedly, the bell on its neck ringing. When it got too far away from us, Don would blow a whistle to call it back.

Then the pointer froze. Its bell stopped ringing, and a moment of silence fell upon the field. Don stepped forward in the direction of the pointer's nose. As he kicked in the bushes, a bird took flight. "Shoot it!" Don shouted. This time I was ready. I mounted my gun, waited for the bird to clear a distance for 20 yards - shoot it any closer and there will be very little meat left, and took aim and pulled the trigger. Feathers scattered in the air, and the bird fell straight down into the grass.

Don released the retriever, who dashed to the spot where the bird fell. In half a minute it returned with the lifeless bird in its mouth. Don wrestled the bird away and put it in the pocket of his enormous vest. A good shot, Don congratulated me.

We would return home with at least one bird, I thought. We'd driven 3 hours from New York City to this upland preserve in the Catskill, slept the night before in a fly-infested cabin, and paid $360 for the hunt. Our jeans had got all wet from the knee down, and our boots were covered in mud. It would be disappointing to return home empty-handed, and embarrassing to face the friends that we had promised to share our game. Although Yang and I had been shooting clay targets for a couple of years, we had never hunted before. The clay target only flies out when we are ready and call for it; the pheasants are less obedient to our wills.

It turned out, however, that hunting pheasants is not too different from shooting clays, as far as the shooting technique goes. Pheasants are big birds, and they fly rather slowly and in almost straight lines. Although they didn't come out at our bidding, the well-trained pointer gave us plenty of time to prepare for the shots, and Don invariably flushed them out when we were ready. The hunt lasted just short of two hours. The pointer found all ten birds that Don released in the field. I shot two of them, Yang got another two. We also shot one bird together - we fired simultaneously and heard only one shot! The other five birds got away; may they live prosperously until old age.

The irony of hunting with a guide in a preserve is that we never really got to touch the birds. Each time we dropped a bird, the retriever got it back and Don pocketed it for us. After the hunt, the management staff plucked and skinned the birds, and packaged them in vacuum-sealed plastic bags. In the end, we were handed nicely packaged pheasant breasts at check-out. Aside from a few residual down left on the wings, they were indistinguishable from a supermarket purchase.

A few days later I baked honey-glazed pheasant breasts. Our guests and we all agreed that they tasted just like chicken.