今日阅读分享

aries 发表于 2009-08-23 00:00:00

姚洋:体制的社会主义与道义的社会主义       

                                                                                                                              
more...
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健康中国组微观计量迷你课

aries 发表于 2009-06-27 17:42:02

为小强和李老师的组员准备的。
 
An Introduction of Introductory Micro-Econometrics
 
References (In the package)
Mostly Harmless Econometrics by Angrist is the good companion for empiricists.
“Recent developments in the econometrics of program evaluation” by Imbens and Wooldridge is a wonderful choice for learning.
I also prepare you a classic paper by Munshi & Rosenzweig (2005 AER) accompanied by a note for better understanding what a convincing empirical work should be like. 
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My best friend's wedding

aries 发表于 2009-06-27 11:51:35

Congratulations, dear Annie! I feel really really happy for you. It's the best day I've spent recently. But now there's no person who's gonna marry me when both of us get to thirty, haha:) Kisssssss.

关键词(Tag): annie
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有关部门该给个说法了

aries 发表于 2009-06-25 00:26:34

gmail, google.com教育网被封解决办法

见北大未名http://bdwm.net/bbs/bbscon.php?board=Google&file=M.1245891104.A&num=4136&attach=0&dig=0
或手动修改DNS

我本来不喜欢阴谋论的.
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政府在下一盘很大的棋亚 事情正在发生变化

aries 发表于 2009-06-24 23:47:12

"绿坝"作用值得肯定 不良网络文化还应治本 新华网嘛

过滤软件,各国如何用  环球时报嘛

谷歌中国涉嫌传播低俗信息 首家被单独点名
2009年5月19日,工业和信息化部印发了《关于计算机预装绿色上网过滤软件的通知》,要求国内计算机生产销售企业在2009年7月1日后出厂和销售的计算机以硬盘预装或随机光盘两种方式预装“绿坝-花季护航”绿色上网过滤软件。其目的就是为了防止未成年人受到互联网不良信息的影响,保护青少年健康成长。巧合的是,在政府大力提倡“绿坝”的同时,谷歌中国再度因传播低俗信息被曝光。

新华传媒调查之:如何肃清网络淫秽色情与低俗信息  什么叫强奸民意

一、你怎样看待谷歌等网站的低俗之风
1:见利忘义
2:社会责任缺失
二、网络低俗在重拳打击之下,目前的状态是
1:仍然很严重
2:大有好转
3:有所好转
三、网络低俗之风的危害
1:腐蚀社会,特别是未成年人
2:损害社会稳定
3:影响国家形象
四、你对打击、整顿网络色情低俗之风的态度
1:坚决支持
2:严惩不怠
五、如何才能有效抑制网络低俗
1:加强行业自律
2:技术手段保障绿色空间
3:健全法制,严格监管,该罚罚、该关关


事情正在发生变化

西方社交网站卷入伊朗危机 帮伊反对派搞串联 youtube twitter flicker google gmail 下一个会是谁?

“高也”也敏感了,不信你试试
还有,新入学的北大新生们要被派上国庆阅兵了~~不知"自发"打出什么标语来,关注关注

为五毛党喝彩!

以下来自维基百科,网络评论员辞条 自然被封,需要代理

对于表现突出,引导得力的网评员,党会给予奖励。例如新华网2007年度优秀网评人评选,共有10名评论员获奖,他们分别是:余丰慧,李克杰,亦菲,郭松民,赵志疆,石飞,艾琳(谭浩俊),毛建国,陈一舟,倪洋军(排名不分先后)。 其中获奖人亦菲的“喝彩”系列网评以喝彩而闻名,他表示,发一篇文章可拿四五十元。

五毛党合影

喝彩系列网评(大多发表于“中国共产党新闻网”上,以评论员文章形式出现):
《为墨西哥疫区航班如期抵上海喝彩》 
《为坊间语言入政府工作报告喝彩》 
《为“世界第一坝”简朴庆典喝彩》 
《为刘淇的定力喝彩》 
《为张艺谋又一个100分喝彩》 
《为外交部发言人幽默回答“鞋袭”问题喝彩》 
《为省委书记的“探索观”喝彩》 
《为陈冯富珍当选世卫组织总干事喝彩》 
《为<资本论>搬上舞台喝彩》 
《为五星红旗“飘扬”太空喝彩》 
《为中南海的“问计”喝彩》 
《为毛家第三代无意“政治”喝彩》 
《为法总统的正确决定喝彩》 
《为又一个一百分喝彩》 
《为“没有零就业家庭”喝彩》 
《为政协民主监督“精品意识”喝彩》 
《为“抛头露面”的十七大代表喝彩》 
《秉公碰硬引公众喝彩 发改委成"发火委"有啥不好》 
《从温总理“为双方喝彩”说开去》 
《大部制,“大步”走,人们理所当然为之喝彩,为之击掌!》 


谢谢kot配图

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加油 加油

aries 发表于 2009-06-24 00:54:40

工作 跑步 游泳 睡觉
a little bit tired. 
+u +u

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Edward Murrow 1958 Speech

aries 发表于 2009-06-21 11:22:30

爱德华·R·莫罗(Edward R.Murrow)1958年在芝加哥举办的广播电视新闻主管协会与基金会晚宴上的讲话。供CCTV参考。




Edward R. Murrow 1958 Speech


RTNDA Convention, Chicago
October 15, 1958

This just might do nobody any good. At the end of this discourse a few people may accuse this reporter of fouling his own comfortable nest, and your organization may be accused of having given hospitality to heretical and even dangerous thoughts. But the elaborate structure of networks, advertising agencies and sponsors will not be shaken or altered. It is my desire, if not my duty, to try to talk to you journeymen with some candor about what is happening to radio and television.

I have no technical advice or counsel to offer those of you who labor in this vineyard that produces words and pictures. You will forgive me for not telling you that instruments with which you work are miraculous, that your responsibility is unprecedented or that your aspirations are frequently frustrated. It is not necessary to remind you that the fact that your voice is amplified to the degree where it reaches from one end of the country to the other does not confer upon you greater wisdom or understanding than you possessed when your voice reached only from one end of the bar to the other. All of these things you know.

You should also know at the outset that, in the manner of witnesses before Congressional committees, I appear here voluntarily-by invitation-that I am an employee of the Columbia Broadcasting System, that I am neither an officer nor a director of that corporation and that these remarks are of a "do-it-yourself" nature. If what I have to say is responsible, then I alone am responsible for the saying of it. Seeking neither approbation from my employers, nor new sponsors, nor acclaim from the critics of radio and television, I cannot well be disappointed. Believing that potentially the commercial system of broadcasting as practiced in this country is the best and freest yet devised, I have decided to express my concern about what I believe to be happening to radio and television. These instruments have been good to me beyond my due. There exists in mind no reasonable grounds for personal complaint. I have no feud, either with my employers, any sponsors, or with the professional critics of radio and television. But I am seized with an abiding fear regarding what these two instruments are doing to our society, our culture and our heritage.

Our history will be what we make it. And if there are any historians about fifty or a hundred years from now, and there should be preserved the kinescopes for one week of all three networks, they will there find recorded in black and white, or color, evidence of decadence, escapism and insulation from the realities of the world in which we live. I invite your attention to the television schedules of all networks between the hours of 8 and 11 p.m., Eastern Time. Here you will find only fleeting and spasmodic reference to the fact that this nation is in mortal danger. There are, it is true, occasional informative programs presented in that intellectual ghetto on Sunday afternoons. But during the daily peak viewing periods, television in the main insulates us from the realities of the world in which we live. If this state of affairs continues, we may alter an advertising slogan to read: LOOK NOW, PAY LATER.

For surely we shall pay for using this most powerful instrument of communication to insulate the citizenry from the hard and demanding realities which must be faced if we are to survive. I mean the word survive literally. If there were to be a competition in indifference, or perhaps in insulation from reality, then Nero and his fiddle, Chamberlain and his umbrella, could not find a place on an early afternoon sustaining show. If Hollywood were to run out of Indians, the program schedules would be mangled beyond all recognition. Then some courageous soul with a small budget might be able to do a documentary telling what, in fact, we have done--and are still doing--to the Indians in this country. But that would be unpleasant. And we must at all costs shield the sensitive citizens from anything that is unpleasant.

I am entirely persuaded that the American public is more reasonable, restrained and more mature than most of our industry's program planners believe. Their fear of controversy is not warranted by the evidence. I have reason to know, as do many of you, that when the evidence on a controversial subject is fairly and calmly presented, the public recognizes it for what it is--an effort to illuminate rather than to agitate.

Several years ago, when we undertook to do a program on Egypt and Israel, well-meaning, experienced and intelligent friends shook their heads and said, "This you cannot do--you will be handed your head. It is an emotion-packed controversy, and there is no room for reason in it." We did the program. Zionists, anti-Zionists, the friends of the Middle East, Egyptian and Israeli officials said, with a faint tone of surprise, "It was a fair count. The information was there. We have no complaints."

Our experience was similar with two half-hour programs dealing with cigarette smoking and lung cancer. Both the medical profession and the tobacco industry cooperated in a rather wary fashion. But in the end of the day they were both reasonably content. The subject of radioactive fall-out and the banning of nuclear tests was, and is, highly controversial. But according to what little evidence there is, viewers were prepared to listen to both sides with reason and restraint. This is not said to claim any special or unusual competence in the presentation of controversial subjects, but rather to indicate that timidity in these areas is not warranted by the evidence.

Recently, network spokesmen have been disposed to complain that the professional critics of television have been "rather beastly." There have been hints that somehow competition for the advertising dollar has caused the critics of print to gang up on television and radio. This reporter has no desire to defend the critics. They have space in which to do that on their own behalf. But it remains a fact that the newspapers and magazines are the only instruments of mass communication which remain free from sustained and regular critical comment. If the network spokesmen are so anguished about what appears in print, let them come forth and engage in a little sustained and regular comment regarding newspapers and magazines. It is an ancient and sad fact that most people in network television, and radio, have an exaggerated regard for what appears in print. And there have been cases where executives have refused to make even private comment or on a program for which they were responsible until they heard'd the reviews in print. This is hardly an exhibition confidence.

The oldest excuse of the networks for their timidity is their youth. Their spokesmen say, "We are young; we have not developed the traditions nor acquired the experience of the older media." If they but knew it, they are building those traditions, creating those precedents everyday. Each time they yield to a voice from Washington or any political pressure, each time they eliminate something that might offend some section of the community, they are creating their own body of precedent and tradition. They are, in fact, not content to be "half safe."

Nowhere is this better illustrated than by the fact that the chairman of the Federal Communications Commission publicly prods broadcasters to engage in their legal right to editorialize. Of course, to undertake an editorial policy, overt and clearly labeled, and obviously unsponsored, requires a station or a network to be responsible. Most stations today probably do not have the manpower to assume this responsibility, but the manpower could be recruited. Editorials would not be profitable; if they had a cutting edge, they might even offend. It is much easier, much less troublesome, to use the money-making machine of television and radio merely as a conduit through which to channel anything that is not libelous, obscene or defamatory. In that way one has the illusion of power without responsibility.

So far as radio--that most satisfying and rewarding instrument--is concerned, the diagnosis of its difficulties is rather easy. And obviously I speak only of news and information. In order to progress, it need only go backward. To the time when singing commercials were not allowed on news reports, when there was no middle commercial in a 15-minute news report, when radio was rather proud, alert and fast. I recently asked a network official, "Why this great rash of five-minute news reports (including three commercials) on weekends?" He replied, "Because that seems to be the only thing we can sell."

In this kind of complex and confusing world, you can't tell very much about the why of the news in broadcasts where only three minutes is available for news. The only man who could do that was Elmer Davis, and his kind aren't about any more. If radio news is to be regarded as a commodity, only acceptable when saleable, then I don't care what you call it--I say it isn't news.

My memory also goes back to the time when the fear of a slight reduction in business did not result in an immediate cutback in bodies in the news and public affairs department, at a time when network profits had just reached an all-time high. We would all agree, I think, that whether on a station or a network, the stapling machine is a poor substitute for a newsroom typewriter.

One of the minor tragedies of television news and information is that the networks will not even defend their vital interests. When my employer, CBS, through a combination of enterprise and good luck, did an interview with Nikita Khrushchev, the President uttered a few ill-chosen, uninformed words on the subject, and the network practically apologized. This produced a rarity. Many newspapers defended the CBS right to produce the program and commended it for initiative. But the other networks remained silent.

Likewise, when John Foster Dulles, by personal decree, banned American journalists from going to Communist China, and subsequently offered contradictory explanations, for his fiat the networks entered only a mild protest. Then they apparently forgot the unpleasantness. Can it be that this national industry is content to serve the public interest only with the trickle of news that comes out of Hong Kong, to leave its viewers in ignorance of the cataclysmic changes that are occurring in a nation of six hundred million people? I have no illusions about the difficulties reporting from a dictatorship, but our British and French allies have been better served--in their public interest--with some very useful information from their reporters in Communist China.

One of the basic troubles with radio and television news is that both instruments have grown up as an incompatible combination of show business, advertising and news. Each of the three is a rather bizarre and demanding profession. And when you get all three under one roof, the dust never settles. The top management of the networks with a few notable exceptions, has been trained in advertising, research, sales or show business. But by the nature of the coporate structure, they also make the final and crucial decisions having to do with news and public affairs. Frequently they have neither the time nor the competence to do this. It is not easy for the same small group of men to decide whether to buy a new station for millions of dollars, build a new building, alter the rate card, buy a new Western, sell a soap opera, decide what defensive line to take in connection with the latest Congressional inquiry, how much money to spend on promoting a new program, what additions or deletions should be made in the existing covey or clutch of vice-presidents, and at the same time-- frequently on the same long day--to give mature, thoughtful consideration to the manifold problems that confront those who are charged with the responsibility for news and public affairs.

Sometimes there is a clash between the public interest and the corporate interest. A telephone call or a letter from the proper quarter in Washington is treated rather more seriously than a communication from an irate but not politically potent viewer. It is tempting enough to give away a little air time for frequently irresponsible and unwarranted utterances in an effort to temper the wind of criticism.

Upon occasion, economics and editorial judgment are in conflict. And there is no law which says that dollars will be defeated by duty. Not so long ago the President of the United States delivered a television address to the nation. He was discoursing on the possibility or probability of war between this nation and the Soviet Union and Communist China--a reasonably compelling subject. Two networks CBS and NBC, delayed that broadcast for an hour and fifteen minutes. If this decision was dictated by anything other than financial reasons, the networks didn't deign to explain those reasons. That hour-and-fifteen-minute delay, by the way, is about twice the time required for an ICBM to travel from the Soviet Union to major targets in the United States. It is difficult to believe that this decision was made by men who love, respect and understand news.

So far, I have been dealing largely with the deficit side of the ledger, and the items could be expanded. But I have said, and I believe, that potentially we have in this country a free enterprise system of radio and television which is superior to any other. But to achieve its promise, it must be both free and enterprising. There is no suggestion here that networks or individual stations should operate as philanthropies. But I can find nothing in the Bill of Rights or the Communications Act which says that they must increase their net profits each year, lest the Republic collapse. I do not suggest that news and information should be subsidized by foundations or private subscriptions. I am aware that the networks have expended, and are expending, very considerable sums of money on public affairs programs from which they cannot hope to receive any financial reward. I have had the privilege at CBS of presiding over a considerable number of such programs. I testify, and am able to stand here and say, that I have never had a program turned down by my superiors because of the money it would cost.

But we all know that you cannot reach the potential maximum audience in marginal time with a sustaining program. This is so because so many stations on the network--any network--will decline to carry it. Every licensee who applies for a grant to operate in the public interest, convenience and necessity makes certain promises as to what he will do in terms of program content. Many recipients of licenses have, in blunt language, welshed on those promises. The money-making machine somehow blunts their memories. The only remedy for this is closer inspection and punitive action by the F.C.C. But in the view of many this would come perilously close to supervision of program content by a federal agency.

So it seems that we cannot rely on philanthropic support or foundation subsidies; we cannot follow the "sustaining route"--the networks cannot pay all the freight--and the F.C.C. cannot or will not discipline those who abuse the facilities that belong to the public. What, then, is the answer? Do we merely stay in our comfortable nests, concluding that the obligation of these instruments has been discharged when we work at the job of informing the public for a minimum of time? Or do we believe that the preservation of the Republic is a seven-day-a-week job, demanding more awareness, better skills and more perseverance than we have yet contemplated.

I am frightened by the imbalance, the constant striving to reach the largest possible audience for everything; by the absence of a sustained study of the state of the nation. Heywood Broun once said, "No body politic is healthy until it begins to itch." I would like television to produce some itching pills rather than this endless outpouring of tranquilizers. It can be done. Maybe it won't be, but it could. Let us not shoot the wrong piano player. Do not be deluded into believing that the titular heads of the networks control what appears on their networks. They all have better taste. All are responsible to stockholders, and in my experience all are honorable men. But they must schedule what they can sell in the public market.

And this brings us to the nub of the question. In one sense it rather revolves around the phrase heard frequently along Madison Avenue: The Corporate Image. I am not precisely sure what this phrase means, but I would imagine that it reflects a desire on the part of the corporations who pay the advertising bills to have the public image, or believe that they are not merely bodies with no souls, panting in pursuit of elusive dollars. They would like us to believe that they can distinguish between the public good and the private or corporate gain. So the question is this: Are the big corporations who pay the freight for radio and television programs wise to use that time exclusively for the sale of goods and services? Is it in their own interest and that of the stockholders so to do? The sponsor of an hour's television program is not buying merely the six minutes devoted to commercial message. He is determining, within broad limits, the sum total of the impact of the entire hour. If he always, invariably, reaches for the largest possible audience, then this process of insulation, of escape from reality, will continue to be massively financed, and its apologist will continue to make winsome speeches about giving the public what it wants, or "letting the public decide."

I refuse to believe that the presidents and chairmen of the boards of these big corporations want their corporate image to consist exclusively of a solemn voice in an echo chamber, or a pretty girl opening the door of a refrigerator, or a horse that talks. They want something better, and on occasion some of them have demonstrated it. But most of the men whose legal and moral responsibility it is to spend the stockholders' money for advertising are removed from the realities of the mass media by five, six, or a dozen contraceptive layers of vice-presidents, public relations counsel and advertising agencies. Their business is to sell goods, and the competition is pretty tough.

But this nation is now in competition with malignant forces of evil who are using every instrument at their command to empty the minds of their subjects and fill those minds with slogans, determination and faith in the future. If we go on as we are, we are protecting the mind of the American public from any real contact with the menacing world that squeezes in upon us. We are engaged in a great experiment to discover whether a free public opinion can devise and direct methods of managing the affairs of the nation. We may fail. But we are handicapping ourselves needlessly.

Let us have a little competition. Not only in selling soap, cigarettes and automobiles, but in informing a troubled, apprehensive but receptive public. Why should not each of the 20 or 30 big corporations which dominate radio and television decide that they will give up one or two of their regularly scheduled programs each year, turn the time over to the networks and say in effect: "This is a tiny tithe, just a little bit of our profits. On this particular night we aren't going to try to sell cigarettes or automobiles; this is merely a gesture to indicate our belief in the importance of ideas." The networks should, and I think would, pay for the cost of producing the program. The advertiser, the sponsor, would get name credit but would have nothing to do with the content of the program. Would this blemish the corporate image? Would the stockholders object? I think not. For if the premise upon which our pluralistic society rests, which as I understand it is that if the people are given sufficient undiluted information, they will then somehow, even after long, sober second thoughts, reach the right decision--if that premise is wrong, then not only the corporate image but the corporations are done for.

There used to be an old phrase in this country, employed when someone talked too much. It was: "Go hire a hall." Under this proposal the sponsor would have hired the hall; he has bought the time; the local station operator, no matter how indifferent, is going to carry the program-he has to. Then it's up to the networks to fill the hall. I am not here talking about editorializing but about straightaway exposition as direct, unadorned and impartial as falliable human beings can make it. Just once in a while let us exalt the importance of ideas and information. Let us dream to the extent of saying that on a given Sunday night the time normally occupied by Ed Sullivan is given over to a clinical survey of the state of American education, and a week or two later the time normally used by Steve Allen is devoted to a thoroughgoing study of American policy in the Middle East. Would the corporate image of their respective sponsors be damaged? Would the stockholders rise up in their wrath and complain? Would anything happen other than that a few million people would have received a little illumination on subjects that may well determine the future of this country, and therefore the future of the corporations? This method would also provide real competition between the networks as to which could outdo the others in the palatable presentation of information. It would provide an outlet for the young men of skill, and there are some even of dedication, who would like to do something other than devise methods of insulating while selling.

There may be other and simpler methods of utilizing these instruments of radio and television in the interests of a free society. But I know of none that could be so easily accomplished inside the framework of the existing commercial system. I don't know how you would measure the success or failure of a given program. And it would be hard to prove the magnitude of the benefit accruing to the corporation which gave up one night of a variety or quiz show in order that the network might marshal its skills to do a thorough-going job on the present status of NATO, or plans for controlling nuclear tests. But I would reckon that the president, and indeed the majority of shareholders of the corporation who sponsored such a venture, would feel just a little bit better about the corporation and the country.

It may be that the present system, with no modifications and no experiments, can survive. Perhaps the money-making machine has some kind of built-in perpetual motion, but I do not think so. To a very considerable extent the media of mass communications in a given country reflect the political, economic and social climate in which they flourish. That is the reason ours differ from the British and French, or the Russian and Chinese. We are currently wealthy, fat, comfortable and complacent. We have currently a built-in allergy to unpleasant or disturbing information. Our mass media reflect this. But unless we get up off our fat surpluses and recognize that television in the main is being used to distract, delude, amuse and insulate us, then television and those who finance it, those who look at it and those who work at it, may see a totally different picture too late.

I do not advocate that we turn television into a 27-inch wailing wall, where longhairs constantly moan about the state of our culture and our defense. But I would just like to see it reflect occasionally the hard, unyielding realities of the world in which we live. I would like to see it done inside the existing framework, and I would like to see the doing of it redound to the credit of those who finance and program it. Measure the results by Nielsen, Trendex or Silex-it doesn't matter. The main thing is to try. The responsibility can be easily placed, in spite of all the mouthings about giving the public what it wants. It rests on big business, and on big television, and it rests at the top. Responsibility is not something that can be assigned or delegated. And it promises its own reward: good business and good television.

Perhaps no one will do anything about it. I have ventured to outline it against a background of criticism that may have been too harsh only because I could think of nothing better. Someone once said--I think it was Max Eastman--that "that publisher serves his advertiser best who best serves his readers." I cannot believe that radio and television, or the corporation that finance the programs, are serving well or truly their viewers or listeners, or themselves.

I began by saying that our history will be what we make it. If we go on as we are, then history will take its revenge, and retribution will not limp in catching up with us.

We are to a large extent an imitative society. If one or two or three corporations would undertake to devote just a small traction of their advertising appropriation along the lines that I have suggested, the procedure would grow by contagion; the economic burden would be bearable, and there might ensue a most exciting adventure--exposure to ideas and the bringing of reality into the homes of the nation.

To those who say people wouldn't look; they wouldn't be interested; they're too complacent, indifferent and insulated, I can only reply: There is, in one reporter's opinion, considerable evidence against that contention. But even if they are right, what have they got to lose? Because if they are right, and this instrument is good for nothing but to entertain, amuse and insulate, then the tube is flickering now and we will soon see that the whole struggle is lost.

This instrument can teach, it can illuminate; yes, and it can even inspire. But it can do so only to the extent that humans are determined to use it to those ends. Otherwise it is merely wires and lights in a box. There is a great and perhaps decisive battle to be fought against ignorance, intolerance and indifference. This weapon of television could be useful.

Stonewall Jackson, who knew something about the use of weapons, is reported to have said, "When war comes, you must draw the sword and throw away the scabbard." The trouble with television is that it is rusting in the scabbard during a battle for survival. 
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数学家怎样看待他们在社会上的作用

aries 发表于 2009-06-19 13:14:21

出处是魏老师的数学思想讲稿,文章来源是公开的。

瑞士联邦的科学部长Ruth Dreifus 女士在第22届国际数学家大会(ICM1994)开幕式上的讲话:《数学家应该怎样看待他们在社会上的作用》

女士们、先生们:
约在一百年前,1897年,第一届国际数学家大会在苏黎士召开。1932年,大会又在瑞士举行。那次会上,设立了Fields奖作为你们的与诺贝尔奖相当的大奖。这一次是我国第三次担当你们大会的东道主。还没有任何别的国家曾经享有你们科学团体给予的这种荣誉。我肯定:东道主也感激你们的诚意并保佑你们大会成功。我个人来参加大会开幕式感到十分荣幸。这是一个难得的机会得以招待数学界世界大师并参与他们的科学讨论。
如果你们大会的主题是癌症研究或者是现代史,那么一个外行或许比较容易了解讨论的是些什么。与此相反,数学,乍一看来,却象是一种为其自身目的服务的抽象学科,或是一种孤傲的艺术。
两年前,在里约热内卢,联合国科教文组织(UNESCO)发起了“2000世界数学年的倡议。国际数学联盟(IMU)则乘机确定了一种对数学的看法,它的重点是:科学与社会之间的关系。里约热内卢宣言中写道:纯粹与应用数学都是了解世界及其发展的主要钥匙之一。我确信社会需要这些钥匙。但是因为我自己并不是数学家,我不知道这些钥匙能开哪些门,也不知道它们通向哪些地方。我愿向你们请教:数学家是怎样看待他们在社会上的作用的。为了思考数学与社会之间的关系,我向世界上最著名的十几位数学家提了三个问题。我在此对收到的所有答复致谢,前两个问题起因于里约热内卢宣言中提到的纯粹数学与应用数学之间的差异。
第一个问题涉及纯粹数学。纯粹数学似乎只在一个完全独立的王国里运转。所以它的目的不在于对社会是否有用,而在于是否为真理。这些真理之澄澈体现了一种美,于是使纯粹数学升华为一种艺术。但是不同于竖琴家以其音乐取悦于人,纯粹数学家不可能使他的艺术为较广泛的公众所接受。于是,我的问题是:纯粹数学怎么能向资助它发展的国家证明它是一项正当的艺术?
Beno Eckmann说:数学为每一种客观思维设立标准。按照 Friedrich Hirzebruch的看法,没有数学就不会有有组织的逻辑思维Raoul Bott答道:(数学家)猎取的财宝处于一切对世界精确探究的最核心,象这样一种研究必然是任何一个前进中的国家最需要关心的
我同意并确信,作为现代世界的一个基本组成部分是需要有数学思维的。历史上,数学曾是打开启蒙运动大门的钥匙。今天,纯粹数学仍然可以被认为是逻辑思维圣盘的监护人。但是 Roland Bulirsch写道:数学是暗藏的文化Jürgen Moser进一步说:数学不可能为广大观众作为欣赏品来接受。如果这种纯粹数学文化既是暗藏的又是不可接受的,那么它又是怎样表现出自己的实际用途,并证实自己的可以捉摸的结论呢?
Armand Borel阐述道:数学如同一座冰山:沉没在水面之下的、不为公众所见的是纯粹数学的领域,而漂浮于水面之上的、可以看见的顶部则称为应用数学.按照Phillip Griffiths的说法:生活中最奥妙的奇迹之一就是最好的纯粹数学总是坚持按照自身的方式不明显地、不可预料地终于使自己成为有用的东西。”Jürgen Moser还说:要使这封信博得好评,其困难在于对数学发现的重要性的认识往往需要经历较长的时间,必须经历20年或者更长些。不幸的是政治家们总是想要见到非常短期的效果。
肯定不止是政治家,整个社会都是这样。在当今时代,我们对生活中的每件事都追求越来越短的周转期。我们想让投资立即回收,想要得到及时的信息。技术的寿命也愈缩愈短,效率和速度已成为判定人类任何一项活动的基本准则。然而,这是危险的,因为目光太短浅了。
在这种环境当中,非常重要的一点是继续承认:知识是一种体现在其自身之中的价值。数学、哲学或是任何一项基础研究的发展都依赖着这条基本原理。它是我们文明的一个重要组成部分。一旦我们忘了它,我们就损害了自己进步的根源。未来是不可预测的。我们不能用其是否立即有用来作为判定知识的价值的基础。例如Vaughan Jones的工作把三维纽结理论与泛函分析联系了起来,因其内在的价值在你们上次京都大会上被授予了Fields奖。稍后,他的理论被物理学家用到了统计力学中去,又被生物学家用来解释DNA的结构。因此,只有通过上面所说的这种认识,并支持基础研究,整个社会才能够保持科学的持续进步和全面发展。
我们转到应用数学上来.今天,应用数学已经成为一切其它科学的基础,并在现代社会生活中产生了巨大的影响。应用数学已与社会高度联系了起来;而且非常有用,但却失去了它的纯真性。然而,与核物理或基因工程的责任辩论有所不同,我似乎感到很少有关于数学在社会中作用的伦理讨论。因此,我的第二个问题是:是不是在数学中没有这种讨论?
有些数学家认为数学在道义上是中性的.例如René Thom在给我的信上说:数学本身在伦理上是中性的。但是, Michael Atiyah爵士在他的复信中提醒我:原子弹只是在经过大量数学计算之后才造出来的。” Jürgen Moser还指出:著名数学家 Vor Neumann Ulam在这项计划中起了重要作用。”Armand Borel问道:人们是不是应该把数学是炮术或制航导弹的基础这个事实看成一个伦理问题呢?是的,我认为应该如此.
Friedrich Hirzebruch写道:确实大多数数学家不关心(他们的工作的)应用前景.”Beno Eckmann走得更远,他说:数学本身与这些(政治的与伦理的)讨论无关——作为一种纯粹知识性的活动,它不可能被这种讨论所影响。当然,那些从事应用数学的人应当面对(这种)讨论。然而,我不认为在抽象理论与实际应用之间划一条界限就能一股脑地消除伦理问题。我们社会的进步受恩于数学家太多,我们必须在承认他们功绩的同时也提请他们注意自己的责任。Raoul Bott曾向我表达了他的无伦理性的观点:对我们所有人来说,纯真的年代已经过去了。我深信,不仅对科学,而且对大多数人类活动来说,都是这样.今天,依仗科学,我们的社会已经发展了控制自然的强大力量。这种力量使我们能够把握自己的尊严,也迫使我们要为它负起责任。如果说纯真的年代已经过去,那么我们必须承认,取而代之的是责任的时代。
现在转向我最后一个问题:作为科学部长,如果我有可能在瑞士大学里增设10个教授席位的话,那么我应当给数学几席?为什么?
Phillip Gliffith对他的学科十分慷慨,他答道:全部应当给数学科学家。”Gerd Faltings也说:九席给数学,但他爱音乐,他留下一席给竖琴师。Michal Atiyah爵士, Friedrich HirzebruchJürgen Moser则要求四至五席给数学。这差不多是所有答复中的平均数.事实上在今天瑞士每二十个席位中只有一席是给数学的。
令人惊讶的是有些答复只强调自然科学方面的需要。然而当我们考虑所面临的社会问题的复杂性时,我深信,问题的解决要求与自然科学紧密合作的,来自社会与人文科学方面的支持与贡献。
从科学日益增长重要性的角度看,我理解为什么科学家们要求更多的财力投入和更多的教授席位。科学家们愈来愈希望找到我们面临的所有问题的解答。所以你们向社会要求必要的财力是合情合理的。在今天,科学研究至关重要。关于这一点你们不必来说服作为科学部长的我,而是让我们一起来说服公众与国会,来说服纳税人。当国家预算出现巨额赤字的时候,这是一项艰难的任务。问题之一是当我们开汽车或打电话时,人们并没有感觉到在社会生活中科学日益增长的影响。绝大多数老百姓并不意识到在日常生活每件事的背后有科学家们的工作。譬如随便问一个瑞士人10瑞士法朗钞上的头象是谁?们可能答不上来。他们从没有注意到这是 Leonhard Euler。也许根本不知道Euler是什么人。
科学团体所面临的任务是向公众宣传科学的重要性。这是你们的任务,也是我的祝大会成功!谢谢。
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Heckman与Imbens的争论的争论

aries 发表于 2009-06-12 13:24:49

Heckman的意见有两点是值得认真思考的。
第一点,什么是“科学”的理论。他认为科学应满足波普尔的证伪主义,因而我们的“科学”研究路径应该是:
1。提出可被证伪理论假说
2。推导出参数的方向
3。用数据验证
随后,Heckman区别了effect of causes以及cause of effect,他认为目前的实验思路有效仅识别了前者,而放弃了对后者的探究。
 
第二点,他指出了三类计量经济学问题
P1.评估历史上发生过的项目或政策
P2.预测已经施行的政策在另一种环境下会如何表现
P3.(根据经济学理论)预测那些历史上从未实行的政策的可能的表现
 
就“因果性”的涵义和实证方法的目标提到质疑,Heckman的批评无疑是有价值的。但坦率地讲,就估计的有效性而言,我站在Imbens等人一边。就目前而言,Heckman这套文献最大的问题是,它们可以在“哲学上”批评新近的进展,但是他们到目前为止似乎仍然无法回应Lalonde(1986)的挑战。Imbens等人挺刻薄的,呵呵,他们实际上是说,你们提的问题,很对,没错儿,对有些问题,experiment或quasi-experiment确实很困难,但你们至少得告诉我,既然你们承认实验方法在P1这类问题上的有效性,那你们的方法至少得到P1这类问题上跟实验比较接近,不然怎么能让大家相信这套方法可以处理更为宏伟的P2,P3问题呢?
 
Yeah, that’s really mean.
 
对Heckman的两个主要批评,我这样看。第一个问题——因果性。对于“因果性”的定义是仁者见仁的。Heckman眼中的因果性说白了是一套“结构方程”。左边是结果,右边是原因,中间用“经济理论”连起来。“结构方程”就是因果性,只能他还没有被事实证伪,这就是“因果的”。Imbens等人则认为,“因果性”是指“随机的”X造成的对Y的影响,即使这里面的机制我们了解得不清楚。我们可以很容易地理解effect of causes,这正是实验方法要认别的,但究意什么是cause of effect?结构模型是么,那是假设啊。不如让我们暂且忘了计量经济学,问问自己什么是cause of effect,你会发现其实我们的alternative并不多。
 
因此,很难说Heckman意义上的“因果性”比后者更接近科学或物理学。因为几乎所有的经济学命题都在一定的场合下被证伪过,需求定律恐怕也不是定律吧,那么我们也许可以得出,任何经济学理论都不是普遍为真的。“实验文献”实际上注意到了这种“因果性”的局限性(locality),一再强调local是这个道理。但是公允地说,他们的因果性——或者推广一些,经济学的因果性——不是证伪主义的。不管你信不信,实证其实际上是在证实;证伪的论文(比如,一堆不显著的参数)是很难发表出来的(这是劳动经济学令人尊敬的地方,只要做得干净,不显著也是结果)。即使我们确实在一个场合下证伪了一个理论,往往也是为了排除一种机制,证实另一种机制罢了。
 
再推一步,如果要问经济学的“科学性”,我个人认为,社会科学不是科学,或者它是软科学,是“基于常识的共识”,具有很强的地方性和历史性。当然也可再推一步,问问自然科学的“科学性”,就回到科学哲学的千古命题了。对这部分讨论,可以参考汪丁丁老师的《知识、秩序、悟性浅说》,是对“科学主义”的一个反思。
 
第二个问题:实证方法的目标。我赞同沈老师的观点,我们必须深入思索某种“效应”的机制。可能与我先前的表述略有矛盾,我也支持“证伪主义”在经济学中的适当应用。但是,证伪的,应该是经济理论,而非“计量经济学模型”,因为后者只是工具,在我看来,它永远是对现实的近似。Heckman似乎弄混了这一点。而就证伪经济理论而言,“实验方法”同样是有效的,同样可以讨论机制。我们可以也应该批评internal validity的适用范围,但当在各种环境中的实验屡次地出现了相似的结果,我们就可以较有信心地将这种validity向外、向不同环境、不同制度背景延展。这比“不证伪”一个“计量经济模型”来验证“因果性”给人更多的信心。而且,它既没有违反证伪主义,也更接近物理学的受控实验方法。注意,这里所指的“实验”是广义的,可以是IV,可是RD,也可以是自然实验或其他拟实验。
 
再退一步讲,其实我们可以用“实验方法”——因为它有很强的internal validity——来验证一个结构模型的有效性。如果用两种方法估计出的结果是接近的,也许可以说结构模型的设定还不错。但反过来,我们不能因为一个结构模型讨论了可能的机制,就认为它一定是正确,因为社会是一个复杂系统,我们不可能把握其中所有的奥秘和机制。

相关讨论及更有趣的争论,见http://forum.ccer.edu.cn/showtopic-87206-1.aspx#334768
关键词(Tag): 计量经济学
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某人说眼神很像偶~

aries 发表于 2009-06-11 19:08:35



三角眼嘛~~
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垃圾

aries 发表于 2009-06-07 20:37:14

今天看到上海的高考作文题,大失所望。高考无疑是中国教育的指挥棒.如此题目,毫无复杂性可言,究竟是要把年青学子的精力引向何处,是空泛的议论还是华丽的辞藻,还是把高考作为向学生贯输官方意识形态的工具?请问这种垃圾题有什么角度可选,什么意见可立?高考要底是在考什么?还是我太幼稚了,不能体会考官出题的深意?转型期的中国有这么多问题要去关心,为什么我们就找不到能让考生自由表达自己思想一个题目。问一声,同学,你对这个问题怎么看?

横向对比一下,就是为学子们所不齿的美国研究生成绩记录考试(GRE),其任何一道作文题(题库公开)都比中国考官的苦思冥起设为国家最高机密的考题要复杂和“有趣”得多.随便举几例:
 
Issue
17.有两种法律:公平的和不公平的。社会中的每个人都应该遵守公平的法律,更重要的是,应该不遵守或者违抗不公平的法律
104.一种文化要想保留它认为好的东西,消除它认为不好的东西,最重要的是通过正规的教育。
161. 在媒体覆盖率很大的当今社会,人们不可能把一个人当作英雄。任何有威望的人在媒体强烈的“关注”下都会名声扫地。
176.科学的目的是打消疑虑,艺术的目的是颠覆。只有这样,它们才有价值。
186. 在任何领域,只有那个领域的专家做出的批评和判断才是有实际价值的



2009上海卷高考作文题。

根据以下材料选取一个角度,自拟题目,写一篇作文。 
  【要求】①自选角度,自行立意。②除诗歌外,文体不限。③不少于800字。
  郑板桥的书法,用隶书参以行楷,非隶非楷,非古非今,俗称“板桥体”。他的作品单个字体看似歪歪斜斜,但总体感觉错落有致,别有韵味,有人说“这种作品不可无一,不可有二”。

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讨论
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L

我觉得这和想要考察的东西不同有关。

高考作文仍算在“语文卷”里,官方欲考察的主要是想象力和表达能力。中国一直很强调写作的想象力这一层面,对于新概念作文思想的沿袭、对于非素质教育的攻击都有推波助澜。各种各样的“作家”得到保送也是重视想象力的证据。另外亦和评卷标准有关。带有价值观取向的题目很难客观评改,故剔除过于主观的立论可能,在官方看来或许是必要的。更不用说这是个连space都要封杀的体系,大部分考生潜移默化之下估计也只敢中庸。

至于GRE,个人理解主要是考逻辑和表达能力。其评改标准不怎么欣赏想象力,这样看来高考作文的体系还更有弹性了。话说回来,很多人倒觉得高考应该愈客观愈好,这样能减少投机取巧的可能性,有投机可能便会有寻租。

我总觉得中国大大小小的制度虽有各种攻击的可能,但它们总是在一个“狭窄的政策走廊”中的折中办法。仔细想想亦有向其妥协的道理。anyway,存在即有理,或许是这样。

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徐小青

你说的非常有道理,我很同意.尤其同意你说的"相对客观".因为比如圆明园兽首这样的题目,我实在对阅卷人的能力心存疑虑,要是他是个小左,或是小右,或者脑残,启不更埋没英才?可能问题更大.但是我不同意"存在即合理",这是对黑格尔的误读,黑格尔这句话其实是想说,存在的是真实的(real),因为它必会走向灭亡.

我们只能寄希望于"优秀人才"在辞藻(或表达)和虚伪的抒情(或揣摩圣意)方面也能胜人一筹.但这是一个很强的假设.与其说是追求"客观",不如说是愚民,最好你没有观点.转一位尊敬的老师写给我的邮件,我相信这正是我想说的(这位老师是著名的自由主义者,可别误会成他鼓吹皇权哟):

Yiqing,果如你所批评的,同意,主要问题是不能诱发复杂思考。这是我们的高考制度不如古代科举制度的要害之处。因为,科举最终需要与皇帝对话,其中有“策问”这样的治国方略,必须复杂思考。我们的教育部却从来不需要通过考试制度来选择什么国策人才。所以,独裁与独裁,还有区别呢。我们的独裁,是“集体领导”,所以,无人负责,只有官僚化而已。皇帝独裁,却是个人负责,殃及家族,必须选贤任能。

关键词(Tag): 高考
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祝福老曾

aries 发表于 2009-06-07 13:22:32

且行且珍惜.



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