2011年12月30日 07:18 AM
小心被隨機性欺騙
In love as in equities, we are regularly fooled by randomness
英國《金融時報》專欄作家 約翰•凱
As the year ends, the author of a weekly column should look back and acknowledge the things he got wrong. I made at least one serious mistake. I wrote that if men think about sex on average every seven seconds, the average man last thought about sex three and a half seconds ago. I should have consulted the poet Wendy Cope, who wrote that: “Bloody men are like bloody buses – / You wait for about a year / And as soon as one approaches your stop / Two or three others appear”.
到了年底，每週發表一篇文章的專欄作家應當回顧這一年，承認自己的文章在哪些地方出過錯誤。我就至少出過一次嚴重的錯誤。我曾寫道，如果男人平均每7秒就想到一次性，那麼男人上一次想到性平均是在3.5秒之前（請見FT中文網2011年9月1日文章《統計數據的誤區》——譯者注）。我本該就此徵詢一下詩人溫迪•可普(Wendy Cope)的意見，因為她曾寫過：“死男人們就像那些可惡的公交車，你一等就得等上將近一年，剛有一輛車靠站，其它幾輛就接二連三地來了。”
Her analogy is helpful. If a bus arrives at fixed intervals of seven minutes, you will wait an average of three and a half minutes. But, as Ms Cope knows all too well, the interval is unpredictable: two buses come at once and then there is a lengthy wait for the next one. The average frequency of the bus may still be seven minutes. But if the intervals are alternately zero and 14 minutes the expected wait is now seven minutes, not three and a half. If someone is standing at a bus stop, it is more likely that they are victim of a bus which is late than the beneficiary of one that is early.
她的類比很有幫助。如果公交車到站的時間間隔是固定的，比如7分鐘，那你平均需要等上3.5分鐘。但實際的時間間隔是無法預知的，可普對這一點了解得很清楚：如果同時來了兩輛車，那麼下一輛就得等上很長時間。公交車到站的平均頻率或許仍是每7分鐘一輛，但如果時間間隔變成了要么是0分鐘要么是14分鐘，那麼預期等待時間就變成了7分鐘、而不是3.5分鐘。如果有人現在正站在公交站等車，那麼他們更有可能是要倒霉地去等一輛晚到的公交車，而不是幸運地趕上一輛早到的公交車。
You may think this does not matter very much. But this summer the UK business secretary Vince Cable asked me to devote an entire year to thinking about equity markets. I discovered that the arithmetic of thinking about share values is the same as the arithmetic of thinking about sex. The average length of time for which buyers hold shares today is very short. But the average length of time for which shares have been held by their current owner is much longer. There are many more high frequency trades than passive investors, but passive investors hold a high proportion of outstanding shares.
你可能會覺得這件事並沒有那麼重要。但今年夏天，英國商務大臣文斯•凱布爾(Vince Cable)讓我花一整年的時間對股票市場做些思考，結果我發現，股票價值思考所適用的計算，與性思考所適用的計算是相同的。現在買股票的人的平均持股時間是很短的，但股票在其當前持有者手中停留的平均時間卻長得多。高頻交易的交易量遠比被動投資者的交易量大得多，但被動投資者所持股票在已發行股票中佔很大比例。
The people queuing for a bus are the people whose bus has not arrived, and the people on yachts are those whose boat came in. What we see will always be influenced by the ways in which the sample studied is selected. The traders we interview are mostly successful because mostly it is the successful who are still trading – and this past success may be no guide to future performance. As the essayist Nassim Taleb has observed, we are regularly fooled by randomness, identifying skill where there was only luck, finding patterns in data when none really exist.
排隊在那兒等公交車的，是還沒等到公交車的人。坐在遊艇上的，則是已買到遊艇的人。我們觀察到的現象，永遠都會受研究樣本選擇方式的影響。我們採訪的交易員大多是成功的，因為大多數情況下，仍在從事交易的人正是那些成功者——但過去的成功並不構成未來表現的指引。正如作家納西姆•塔勒布(Nassim Taleb)觀察到的，我們經常被隨機性所欺騙，在那些只由運氣決定的情況中尋找技巧，在實際上毫無規律的數據中尋找規律。
The sometimes counter-intuitive mathematics of variation crops up in many different places. If Persil is sometimes on special offer, the percentage increase when it goes back to its usual price will be larger than the percentage price reduction when it goes on special. If that seems an unremarkable fact, it was enough to send several hundred thousand government employees on strike a month ago.
有時候，這種與直覺認識相反的、關於“變動”的數學運算也出現在其它地方。如果寶瑩(Persil)洗滌劑偶爾進行一次特價促銷，那麼從特價恢復為原價時價格上漲的百分比，會高於從原價降為特價時價格下跌的百分比。儘管這個事實看似再正常不過，但它卻足以讓數十萬政府工作人員在上月舉行罷工了。
The average of price changes shows an increase even though the price has remained the same. And perhaps you buy more, perhaps even spend more, when the item is on offer than when it is at full price. After all, that is why they put it on special. These issues pose problems for compilers of price indices, and there are different methods of handling them. That is the principal reason why the new European harmonised index of consumer prices generally increases by less than the old retail prices index. The UK chancellor George Osborne is planning to make large savings in public expenditure by shifting pension indexation from one basis to the other.
儘管整個促銷過程結束後價格實際上與原來完全相同，但價格變幅的平均值卻顯示價格出現上漲。當商品處於促銷時，你的購買量甚至購買額很可能會比商品處於原價時要多。畢竟，商家特價促銷的目的就在於此。這些情況給價格指數的編制者造成了麻煩。我們可用多種方法來解決這些麻煩。歐洲新的“消費價格調和指數”(HICP)通常比原先的零售價格指數(RPI)漲幅更小，其主要原因也在於此。英國財政大臣喬治•奧斯本(George Osborne)正打算將編制養老金指數所基的指數從RPI換為HICP，以節省巨額公共開支。
The same problem arises in measuring benchmarks and portfolio performance in equity markets. If you average a 50 per cent fall and a 100 per cent increase, you show a 25 per cent gain. But if that happened to your shares, you would – just – have recouped your initial investment. Neither method of calculation is necessarily a guarantee to the experience of real investors.
在衡量股市基準和投資組合表現時，也會產生相同的問題。將50%的跌幅和100%的漲幅相平均，得到的結果是上漲了25%。但如果這種情況發生在你的股票上，那你就只是收回初始投資而已。這兩種計算方法得出的結果，都未必與投資者在現實中的感受相符。
I may have made another mistake in my earlier column. Since it appeared, details have been published of a study by researchers at Ohio State University. They surveyed college students – who, one might expect, think about sex more often than the average of the population. The subjects were asked to make a note each time the topic entered their heads. Men thought about sex, on average, 19 times a day (the figure for women was only 10). Does this mean that we should correct “every seven seconds” to “on average, once every waking hour”? Only if men think about sex at absolutely regular intervals. And neither love nor equity markets are so predictable.
在先前的專欄文章中，我可能還出過另一個錯誤。那篇文章發表後，俄亥俄州立大學(Ohio State University)的研究人員發布了一項調查的詳細結果。人們可能認為大學生想到性的頻率比一般人高，於是研究人員就對大學生進行了調查。他們要求調查對象每次想到性時，就在記錄中記上一筆。結果顯示，男生平均每天有19次想到性（女生則只有10次）。這是不是意味著，應該把“每7秒”修改成“醒著的時候平均每小時想到一次”？不見得，除非男人想到性的時間間隔是絕對固定的。而且，無論是預測愛情還是預測股市，都沒那麼容易。
譯者/何黎
2011年12月29日 星期四
2011年12月26日 星期一
《可靠性入門》Reliability by Arnold Kaufmann
1983年11月8日(我近30年之後才注意到出版日)，台北的徐氏基金會出版我翻譯的《可靠性入門》Reliability by Arnold Kaufmann (Paperback - 1972)。我的「編譯序」如下：
《可靠性入門》譯序
「可靠性」這門學問，經過數十年來的研究和應用，已成為系統科學的一大主流。然而其文獻和資料太過艱難和浩瀚，所以青年學者每每不得其門而入，只有望「可靠性」而興嘆。鄙人有感於此，特根據昔日留英所購之一本精彩導論，編譯了惡本《可靠性入門》。原書為斐譽世界的法國數學家 M. ARNOLD KAUFMANN 等人為法國的青年所寫，由於深入淺出，精彩無比，所以英國的空中 (開放)大學列為參考書。
本書旨在幫助青年學生 (高中生就可以)和社會人士了解「可靠性」這門日益重要的學問》所以但求能言簡意賅，能幫助讀者很快掌握「可靠性」，並用許多例子來輔助關鍵性概念的說明，希望這種刻意安排，能幫助讀者很快掌握「可靠性」的各重要主題。
本書所探討的概念，對於有志成為科學家(如生物學家) 、工程師 (可靠性的許多經驗和需求，都是源自工程學)社會科學家(如保險精算師、應用統計學家)的青年，都是必備的修養和和工具。可靠性所探討的生命曲線(Mortality Curve )適用於各種生物、工程和人文現象，只是其實際曲線之形狀，要依各系統(不論是電子、機械或生物)的可靠性而定。本書的另一特色，是對基本兒重要的可靠性原理，都有淺顯兒深入的介紹，誠為一本不可多得的入門書。有心想進一步研究的青年朋友，請不吝向編譯者連絡。
感謝電子工業研究所的嚴強先生的耐心謄稿，也謝謝徐氏基金會的慨允出版，了卻鄙人的一樁心願。本書如有什麼缺點，那是鄙人的責任，請指教。
目錄
編譯序
前言
可靠的評價
殘存律
基本概念：故障率
主要殘存分布
器材不再是新的時
器材來源不齊一時
一個數值例子
系統故障的邏輯
單調結構函數
可靠性網路
可靠性函數
如何增進可靠性
冗餘
抽換
複雜系統的殘存率
基本更生理論
殘存曲線之決定方法
維護
結論 60
參考書目 61
索引 62
作者簡介
他的其他著作(不全)
Introduction to Fuzzy Arithmetic: Theory and Applications (Van Nostrand Reinhold Electrical/Computer Science and Engineering Series) by Arnold Kaufmann, Madan M. Gupta, Arnold Kaufman and Bob Esposito (Paperback - Jul 1991)
The Science of Decision-Making: An Introduction to Praxeology by Arnold. Kaufmann (Paperback - Jan 1968)
Dynamic Programming by Arnold Kaufmann and R. Cruon (Hardcover - Dec 1967)
Graphs, Dynamic Programming and Finite Games by Arnold Kaufmann (Hardcover - Oct 1967)
Introduction to Operations Research by Arnold Kaufmann and R. Faure (Hardcover - Nov 1968)
Integer and Mixed Programming Theory and Applications by Arnold Kaufmann and Arnaud Henry-Labordere (Hardcover - Dec 1977)
Methods and Models of Operations Research by Arnold Kaufmann (Hardcover - Dec 1963)
Science of Decision Making: Introduction to Praxiology by Arnold Kaufmann and R. Audley (Hardcover - Mar 1968)
Fuzzy Mathematical Models in Engineering and Management Science by Arnold Kaufmann (Hardcover - Oct 1988)
Points and Arrows by Arnold Kaufmann (Paperback - Sep 22 1972)
2011年12月22日 星期四
Newt's big
Gingrich drew inspiration from management theorist
Deming led Japan back after WWII
TRANSFORMATIVE: Management guru W. Edwards Deming, seen here in February 1987, found an eager student during the last years of his life in the 1990s in Newt Gingrich. (Associated Press)In March 1992, House Minority Whip Newt Gingrich sent copies of two major speeches to a man about twice his age living in Washington.
The first speech was what Mr. Gingrich referred to as his “basic speech.” He called it “the necessary revolution.” The second was a policy speech he had given to the American Hospital Association about ways to bring down costs.
In a letter along with the speeches, Mr. Gingrich privately confided that he was certain that both speeches “contained significant errors and lack some key principles.”
“If you could read these speeches and identify both the mistakes that are in them and the principles that I have missed that need to be included,” Mr. Gingrich added.
The recipient of the letter was a 91-year-old management guru named W. Edwards Deming, a statistician and consultant credited with helping Japan become a world power after World War II through manufacturing. Mr. Gingrich made no secret of his admiration for Mr. Deming’s teachings while in Congress.
During the last three years of his life - from 1991 to 1993 - Mr. Deming corresponded regularly with Mr. Gingrich. Today, the correspondence shows the presidential candidate, who talks often about his days as a history professor, in the clear role of student.
“I am hereby applying to be an apprentice to you,” Mr. Gingrich said in a handwritten note to Mr. Deming in July 1991 after Mr. Deming visited Congress. “Monday was an historic day in the Capitol,” Mr. Gingrich wrote. “You won a number of converts to ‘profound knowledge.’
“Now we must study and learn,” he wrote, adding that “with your help, training and leadership, I believe we can transform America.”
Mr. Gingrich included a copy of the Congressional Record, which contained Mr. Gingrich’s speech on the floor of the House about Mr. Deming’s visit to the Capitol. On the front page of the document, Mr. Gingrich jotted another note.
“My brief remarks … fail to do justice to the tremendous impact you made on Monday,” Mr. Gingrich wrote. “A number of members, staff and White House people have told me how impressed they are.”
In his House speech, Mr. Gingrich referred to Mr. Deming as “the founder of the quality movement” and added that he was known as “the man who initially in the late 1940s and early 1950s educated the Japanese into the process of quality.”
Aside from advice on the speeches, Mr. Gingrich sought a reading list.
“Every time we meet, I learn more about your philosophy and how deeply it would transform our society,” Mr. Gingrich wrote. “If there are books or articles that profoundly influenced you, I would be glad to read them to get a better understanding of the context of your philosophical development,” he told Mr. Deming.
A spokesman for the Gingrich campaign did not respond to a request for an interview about the correspondence, which is contained in a collection of Mr. Deming’s papers on file at the Library of Congress.
In a letter he sent to Mr. Deming in February 1993, Mr. Gingrich again sought Mr. Deming’s feedback on a speech titled “Renewing America’s Civilization.”
Newt's big week!According to some polls, the bloviating Newt Gingrich is the new GOP front-runner. It won't last(37)不知道此號人物者 請找本blog
Gingrich Gave Push to Clients, Not Just Ideas
By MIKE McINTIRE and JIM RUTENBERG
Newt Gingrich is adamant that he is not a lobbyist, but in the eight years since he started his health care consultancy, he has made millions of dollars while helping companies promote their services.
Gingrich Earned $1.6 Million Calling Freddie Mac 'Insane' Newt Gingrich made at least $1.6 million from consulting contracts with Freddie Mac over a period of eight years, Bloomberg News reports. Asked in a recent debate what he did for Freddie, Mr. Gingrich said he "offered them advice on precisely what they didn't do," calling the mortgage finance company's practices "insane."
2011年12月18日 星期日
Dr. Deming 的教育改革的故事
我上周五晚上在陳文魁 教授主講的
RECOMMENDED: SEA CHANGE
A report from the NEA's Commission on Effective Teachers and Teaching calls for "systemic changes in the [nation's] educational structures by engaging teachers in the decision-making processes that impact student learning." The report urges "moving from a top-down hierarchical model to a circular structure of shared responsibility" that will "engage students as active participants in their own learning."
To place student learning at the center, schooling must transform from a time-oriented system based on grade level and credits earned to a performance-based system aligned to national learning standards. Student learning must be at the center of decisions about instructional models, scheduling, school structure, and flexibility.
To set student-learning goals and assess outcomes, teachers must work in collaborative teams and use professional judgment based on teaching standards and practice. At the same time, teachers must have authority to make instructional and educational management choices and decisions. Teachers must also share in the responsibility for teacher selection, evaluation, and dismissal.
In sum, the teaching profession requires transformational changes in recruitment, selection, preparation, professional learning, evaluation, compensation, and career advancement. This information is from PEN NewsBlast.
報告專題：雲端與我們的未來 (他其實在介紹應付某美國管理學院的認證之科技作法)
我講了許多Dr. Deming 的教育改革的故事..... (2018年8月4補充：當年太懶，沒及時將所講的寫下來，現在後悔莫及......)RECOMMENDED: SEA CHANGE
A report from the NEA's Commission on Effective Teachers and Teaching calls for "systemic changes in the [nation's] educational structures by engaging teachers in the decision-making processes that impact student learning." The report urges "moving from a top-down hierarchical model to a circular structure of shared responsibility" that will "engage students as active participants in their own learning."
To place student learning at the center, schooling must transform from a time-oriented system based on grade level and credits earned to a performance-based system aligned to national learning standards. Student learning must be at the center of decisions about instructional models, scheduling, school structure, and flexibility.
To set student-learning goals and assess outcomes, teachers must work in collaborative teams and use professional judgment based on teaching standards and practice. At the same time, teachers must have authority to make instructional and educational management choices and decisions. Teachers must also share in the responsibility for teacher selection, evaluation, and dismissal.
In sum, the teaching profession requires transformational changes in recruitment, selection, preparation, professional learning, evaluation, compensation, and career advancement. This information is from PEN NewsBlast.
2011年12月5日 星期一
continuous improvement and continuous cost reduction
Op-Ed Columnist
Dr. Berwick’s Pink Slip
By JOE NOCERA
Published: December 5, 2011
Dr. Donald Berwick was already in Massachusetts when I spoke to him Sunday afternoon. He was back in the Newton home where he’d lived for 30 years, being pleasantly interrupted during our conversation by his 2-year-old grandson. His last day in Washington as the administrator of the Centers for Medicare and Medicaid Services had been Thursday. Friday was packing day. Saturday was moving day. And, by Sunday, he was already talking about his too-short, 17-month tenure as the nation’s top Medicare official in the past tense. Which, alas, it was.
Earl Wilson/The New York Times
Joe Nocera
Dr. Berwick, I’m here to tell you, was the most qualified person in the country to run Medicare at this critical juncture, and the fact that he is no longer in the job is the country’s loss. Berwick started out as a pediatrician and health care researcher at the Harvard School of Public Health and eventually became vice president of the Harvard Community Health Plan (now known as Harvard Pilgrim Health Care). There, he became enamored with the ideas being promulgated by management gurus like W. Edwards Deming and companies like Toyota, which believed that companies could create processes — and a mind-set — that would allow for both continuous improvement and continuous cost reduction. Indeed, they believed that the two went hand in hand.
Latching onto these ideas, Berwick helped start — and, for the next 19 years, run — the Institute for Healthcare Improvement, which was devoted to applying them to health care. The result would be healthier patients who spent less time in hospitals — and a culture that wasted less money on things that didn’t lead directly to a healthier population.
As the insurer of one out of every three Americans, Medicare is in an enviable position to push for health care improvements, if it chooses to. And with a budget larger than the Pentagon’s — and a consensus that its spending must be brought under control — no government agency has a more urgent need to cut costs. Surely somebody who has spent his career focused on these two issues would seem to be just the ticket.
But there’s one more thing about Berwick: He believes that President Obama’s health care reform is “an important moral step toward universal health care.” As he put it when we spoke: “Because of it, our country is, at last, making health care a basic human right. It is a majestic thing.”
Naturally, this view made him anathema to Republicans, who blocked his nomination in the usual way. They pored through his old speeches and articles, plucked out a few comments they objected to — he once praised the British health care system! — and announced that they would never confirm him.
President Obama was not deterred the way he had been when Republicans objected to Elizabeth Warren becoming the chief of the new Consumer Financial Protection Bureau. Instead, in July 2010, Obama named Berwick to the post in a recess appointment that did not require Senate confirmation. But, like all recess appointments, it was temporary. Berwick left the post just weeks before his appointment was set to expire.
What did Berwick accomplish in those 17 months? A lot — though not nearly as much as he would have liked to. His focus, as it has always been, was on improving the quality of health care and cutting costs. “On my third day,” he said, “I held a staff meeting for all 5,000 members of the staff, and I said, ‘You all think that you are in the business of paying bills. Yes, you do that. But I also think Medicare can be a force for change.’ ” He added, “I tried to reconceptualize it as an improvement organization.”
As Berwick tells it — and others affirm — the Medicare staff had been hungering for such a mission. “We had a triple aim,” he says. “Better health care. Better health for the overall population. And lower costs. I thought that, my goodness, given the resources and the reach — and the great staff, which was a wonderful surprise — we ought to be able to help health care providers do much better.”
Health insurers and hospitals, who had generally thought of Medicare as little more than a stodgy, bureaucratic insurer, began to see it in a different light as well, as Medicare staffers, trained as “improvement coaches,” began to share ideas and push for simple, sensible steps that would, for instance, keep people with chronic medical problems from having to be constantly readmitted to the hospital.
Of course, 17 months is hardly enough time to complete such a transformation, and it is hard to know if Berwick’s emphasis on quality will stick. What he needed, most of all, was more time — precisely what the Republicans wouldn’t give him.
By refusing to confirm him, Republicans won a pointless victory against the president. But, if the day ever comes when they — and the country — truly get serious about reforming Medicare, they may regret giving a pink slip to the best man for the job.
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