5/19 企業家分享會

Fact of the Day: City Life is Hard!

From "The Logic of Life":

As a rule of thumb, each doubling of city size raises wages by 10 percent but raises prices by 16 percent.

Apparently, this surprising result comes from the data gathered by the foremost economist on cities, Ed Glaeser. So the question is why do people live in cities?





The Answer: Knowledge Spillover...............Huh?

I know my family didn't move to Taipei for this.

Stuck in Murakami Land

最近幾天我都是好幾本書一起看。因為前一陣子太忙了，所以想看的書都沒有看，所以現在囫圇吞棗，一次多本書。

我看的書大部分都事經濟學的書，但是熱愛文學的我也是時常看一些文學作品。我媽媽非常推薦村上春樹，所以我就買了一本 "Blind Willow, Sleeping Woman"。這一本是 Murakami 的第一本短篇小說集。我一相認為要看一個作家的寫作工力，就是要看他的短天小說寫得如何。因為要把一個意境完整且很有創意的在幾頁內闡述是需要極為豐富的想像力與文字駕馭能力。譬如說，在我心目中，Hemingway 就是一位非常優秀的作家，因為他的作品: Hills Like White Elephants 給讀者無限的想像空間，或是他自認為他最滿意的作品:

For sale: baby shoes, never used.

就六個字! 有趣吧! 你認為他在講什麼呢?

那 Murakami 呢? 我只能說，我最近幾天在看他短篇故事時，時間好像過的最快! 他的故事裡的人物就如我們身旁的一些人，迷失了自己的方向的人，失去了愛的人，得不到愛的人，不知道什麼是愛的人。這一些人都會經歷如夢一般的轉折，有一些會找到自己的歸屬，有一些會繼續迷失，但是在故事的過程中，讀者會跟主角一起成長一起發覺。就是這種感覺才會使我繼續讀下去。當然，故事裡的怪異的情境也是使我讀下去的動力。例如，"Nausea 1979" 就是講一位連續40天嘔吐的一位花花公子，而嘔吐前必定接到一通詭異的電話，這件怪事會使我一直讀下去，但是到了最後一句話，Murakami還是沒有跟讀者講說是什麼東西使他嘔吐，而嘔吐跟電話有何關聯。可能嘔吐的原因不重要，然而主角經歷這一件事的過程才是Murakami想表現出來的，可能他只是想表達一個孤獨的人，在腦裡的聯想與心理的反應。他的故事的結局大部分都與故事情節無關，我這麼說的意思是，最後讀者是不會得到一個完整的答案，但是在 Murakami Land 答案不重要吧。

Murakami 絕對已經在我的top ten 的authors 裡了。

搬到台北了!

我已經搬到台北了!!

我星期五就搬到重慶南路三段的新家。我覺得我爸媽很有眼光，選的地方不錯。(就在師大夜市附近，very good!)

我自己在星期五晚上，然後在星期六晚上跟藍柏祥，有做一點 "場勘"。所以若有朋友想要來的話，我知道哪一些好吃的地方可以去。

所以開放報名! 跟我連絡我就帶你吃好吃的玩好玩的。

ps: 我星期五，六與日在台北。

Economists are Needed

Hillary Clinton wants to appeal to the blue collar workers so bad that she is dismissing all educated opinion as elitist, and inconsiderate to the working people of America.

It started with:

“Well I’ll tell you what, I’m not going to put my lot in with economists.”

Then the ignorance was confirmed and continued:





Hillary Clinton is playing dirty. She knows the implications of a gas tax holiday, but she is trying to fool the people and get away with it. I guess she is willing to do anything to win, but this is just insulting the intelligence of the common people, especially to economists.


We are needed.

各為同志! 以後工作有著路了!

高中缺老師阿!!

高中有沒有必要學經濟學? 我認為要，但是頂多了解一下供給與需求，我認為就夠了。至於會不會需要成度與大學一年級的課程一樣，我認為這樣有一點過份了。畢竟，思想上，經濟學事需要夠成熟的人才能夠真正體會他的美，而不至於曲解他的意思。

但是，若有需要，我認為我們念經濟的當高中老師會相當勁爆。

Good Advice

A collection of good advice for young economists.

歐巴馬懂經濟，希拉蕊不懂

從健保到最近的石油稅的問題，歐巴馬的方案都比希拉蕊的好。應該是說希拉蕊的方案太差了。

希拉蕊希望能降低石油稅，在從石油商所多賺的錢抽稅。她希望這方案能夠降低美國人民的石油支出的負擔，也進一步，殺殺石油商的銳氣 (她每一次都在說，go after the oil companies......)。 但是這個方案真能達到此效果嗎?


歐巴馬的回應:

They argue that it would either have little impact or it would have a negative effect by either causing drivers to drive more or oil companies tosimply raise their prices.

這回的太漂亮了，因為希拉蕊的方案的確是會造成這樣的效果。為什麼呢? 就聽一聽 Paul Krugman 的解釋:

Why doesn’t cutting the gas tax this summer make sense? It’s Econ 101 tax incidence theory: if the supply of a good is more or less unresponsive to the price, the price to consumers will always rise until the quantity demanded falls to match the quantity supplied. Cut taxes, and all that happens is that the pretax price rises by the same amount. The McCain gas tax plan is a giveaway to oil companies, disguised as a gift to consumers.

Is the supply of gasoline really fixed? For this coming summer, it is. Refineries normally run flat out in the summer, the season of peak driving. Any elasticity in the supply comes earlier in the year, when refiners decide how much to put in inventories. The McCain/Clinton gas tax proposal comes too late for that. So it’s Econ 101: the tax cut really goes to the oil companies.

The Clinton twist is that she proposes paying for the revenue loss with an excess profits tax on oil companies. In one pocket, out the other. So it’s pointless, not evil. But it is pointless, and disappointing.

所以結論是歐巴馬比較懂經濟學，因此比較適合當總統。

清大幫分享會：遇見繆思，5/5 Mon 19:00@活中101

我第二次當PM，請大家一定要來!!

為什麼要去?

因為許恒瑞會當場作一首曲子，何介夫是我的表哥，周威成會告訴你如何在十字路口做抉擇。

還不來!?

Unintended Consequences: Mexican Driving Edition

A new article in the JPE:

In 1989, the government of Mexico City introduced a program, Hoy No Circula, that bans most drivers from using their vehicles one weekday per week on the basis of the last digit of the vehicle’s license plate. This article measures the effect of the driving restrictions on air quality using high-frequency measures from monitoring stations. Across pollutants and specifications there is no evidence that the restrictions have improved air quality. Evidence from additional sources indicates that the restrictions led to an increase in the total number of vehicles in circulation as well as a change in composition toward high-emissions vehicles.

Enjo Kosai! Part III

我覺得這是我的最後一篇關於援交的了。

有一位熱心的學弟提供了一個網站可以找到真的援交的資訊。但是要加入會員而且文張數量要一定。

我之前的結論是說網路的發展會迫使許多行業找尋其他管道散播訊息，但是這一個網站證明，我們也可以發展新的語言。

我不知道各位有沒有看過，A Clockwork Orange (上了發條的橘子) 這一本書。書本裡的不良少年就用自己創造出的語言彼此交談。這跟我們會用火星文是一樣的道理。因為我們想要與別人有區隔，爸媽聽不懂 "ORZ" 或 "冏" 的意思。

這也是為何為了與詐騙集團有區別，真的援交會用特別的語言與你對話。譬如說，"泡茶" 是指找應召站的，而 "釣魚" 是指找援交。有人說這是怕警察抓，但是我覺得是，但也不是，其實，現在警察不太抓援交了，因為想衝業績的他們，發覺抓同性戀的比較好上勾，所以整個focus已經轉移。但是，也有可能就是因為網路援交設了這麼多進入門檻，所以警察才往同性戀那裡抓。所以一切都已經達到最適狀態。

但是我想argue說這語言的建立是一種signaling。他意謂著一種能力，因為也只有真的才會敢社這麼高的門檻。但是，這個故事有一點說不通。為何，詐騙不學起這套語言，模仿一下真的援交，然後騙一騙錢? 這我就不知道了，有可能現在的詐騙行業還沒有那的競爭吧。

我是隨便亂寫的。

大大大新聞

我今天接到我媽媽打來的電話，她跟我說: "我們要搬到台北住了"

我知道我爸媽想搬到台北，但是他們有再找房子，而且下星期就要住那裡了，蠻突然的。

我還沒有看過房子，聽說在古亭捷運站那。

學而實習之

2500

終於! 我的部落格有2500次的viewing。

現在唯一的問題是，是我上站2500次，還是其實還是有一些忠實讀者?

The Monty Hall Problem

Switch or Don't Switch!? The answer is extremely counterintuitive.

So what is the big deal here?

The economist, M. Keith Chen, has challenged research into cognitive dissonance, including the 1956 experiment that first identified a remarkable ability of people to rationalize their choices. Dr. Chen says that choice rationalization could still turn out to be a real phenomenon, but he maintains that there’s a fatal flaw in the classic 1956 experiment and hundreds of similar ones. He says researchers have fallen for a version of what mathematicians call the Monty Hall Problem, in honor of the host of the old television show, “Let’s Make a Deal.”

Obama the Listener

Cass Sunstein on Obama

Funny but Embarrasing

This is very funny, but so embarrasing at the same time. On a positive note, if you don't have passion, you wouldn't be acting like this. My explanation is that they are passionate people.

What I've Been Up To : 家教

我最近除了當職業學生之外，還有接了另一個工作!

我最近接了家教!

對! 沒有錯! 不是我太無聊沒事做，我其實忙到爆了! 但是，我一項都很喜歡教書的感覺，而這一次學生需要補強的科目也正是我最喜歡教的 : 經濟學。

學生是一位從美國回來的實驗中學學生，而他正在學經濟。然而，第一次碰，難免有一些挫折，加上他中文不好，所以找的家教老師需要會英文又會經濟學又要住在新竹。Hmm，讓我想一想有誰具備這一些條件阿!?

我昨天教他IS-LM，我希望這不會太難。一般而言非常有可能太難，但是我覺得若他會這東西，以後教下去會比較輕鬆。

Studying Economics isn't all that Bad

我爸以前非常希望我念財金，因為收入比照其他行業較為可觀。因此，我決定念經濟之後，還是感覺到我爸時常提醒我 : "余沛成，你唸了經濟之後，還是可以進入金融業阿!" 可惜我的興趣已不在那裡了。現在，我爸非常鼓勵我念經濟，可能看到我一講起經濟的東西，眼睛就亮了起來，也有感動到他吧。


最近的一項調查，會更讓主修經濟的小孩的家長鼓勵他念經濟吧 :



念數學好像也不錯!

Obama almost in a Bill Clintonesque Moment

Funny

What am I reading: The Audacity of Hope

Obama 的書，我才看到第一章，就有一句我感同身受:

.... I'd begun to see how any challenge to convention harbored within it
the possibility of its own excesses and its own orthodoxy. I started to
reexamine my assumptions, and recalled the values my mother and grandmother had taught me. In this slow, fitful process of sorting out what I believed, I began silently registering the point in dorm-room conversations when my college friends and I stopped thinking and slipped into cant: the point at which the denunciations of capitalism or American imperialism came too easily, and the freedom from the constraints of monogamy or religion was proclaimed without fully understanding the value of such constraints, and the role of victim was too readily embraced as a means of shedding responsibility, or asserting entitlement, or claiming moral superiority over those not so victimized.

我在大學時也有過這一段，我猜念社會科學的都會有這類的問題。因為我們的學科挑戰傳統思維的意味很濃，而經濟學理的一些推論是有違社會上的一些規範，這一切都在於我們對於市場的信賴，也刻劃出我們所在意的東西 : 效率。所以我年幼的時候時常以我從一些基本的教科書上學的，批判社會的制度，或是道德的規範，從來都沒有懷疑果經濟學，更沒有問說當初這一些規範是如何演變而來的。然而，學了多一點之後，我發現經濟學理的不足的部分，更看到比效率更重要的一些目標。但是，發現了這個學科的盲點以及缺失，我更熱愛了這個學科，因為他不完美，表示他還有容納我的空間。

Obama 的書裡面有一堆這類的段落，讓你想，讓你體會，讓你感同身受。有一些人說 Obama 只會講一些好聽的話，寫一些感人的文字，但是我覺得若他沒有真材實料，他不可能寫出他寫的這一些東西。非常佩服!

援交妹 (or 詐騙集團) Part II

我上星期四在 Skype 上約了一個 "援交妹"。我的目的是想在網路上找到一個真的援交妹。因為我覺得網路讓整的市場陷入一個Akerlof式的檸檬車市場。於是我決定約那個援交妹出來! 因為他看起來最不像是詐騙的。


先介紹一下這個女的，他說他是隔壁學校的學生，也給了我名子與系級。我用網路查了一下，果真有這個人，他所言不假。我跟他哈拉了將近 5 個小時。在這期間我大部分的口舌都浪費在要他證明自己不是警察或是詐騙。他提供了一些資料，我也反問他一些問題 (他有答的都幾乎答錯，大部分都沒有回答)，最後把她給搞瘋了! 這時我才發覺他可能不是詐騙，也更不是警察 (話說警察很注重效率跟業績，因此都跑去抓同性戀的嫖客!)。原因如下:

1. 他花了很多時間想像我證明自己是援交 (雖然這一些詐騙也能做，但是我沒有遇過詐騙這麼做)

2. 若他是詐騙，他也做了很多功課，都已經準備好名子，也熟習新竹地理。


我最後跟他約在火車站對面的誠品的地下室。但是時間到他沒有出現，也沒有打來。因此我當時想說，她可能是真的援交，並且他不打來就是想證明他自己不是詐騙。最後我回到寢室，用skype跟她聯絡。


她竟然跟我說她有打給我! 但是我沒有接!? 我這時知道她在虎爛並且她沒有打給我不是為了要證明自己不是詐騙。她後來補充，我把她惹火了，現在要見面一定要先匯錢再說。我心碎了! 她竟然是詐騙! 我後來去查看隔壁校的同名同姓同系級的人，不是她! 所以她不是援交，而是搞詐騙的!


我一個月的田野調查竟然全都遇到詐騙!!


我跟我的一個日本的好朋友聊我最近做的東西，他說他之前也有相同的想法，並且靈感來源也是援交妹! 並且很鼓勵我繼續做研究。我問他為何沒有繼續做? 他說因為這種田野調查太恐怖，不值得。我想我也應該收手了!

My First Time as a PM for a Seminar

如何找一個真的援交妹?

好像無法在網路上找! 這是我一個月下來的研究成果。

一方面網路太容易形成 pooling，搞的嫖客都分不清是詐騙，是警察，還是無聊人士，或是是真的援交。這對援交來講是很大的問題，對顧客來說是也是很大的問題。

我一直以為援交有方法在網路上證明自己是真的援交，但是看來在網路這個管道下是無法的，因為網路提供的驗明正身的資源太少 (或是太多?)，所以要說什麼或做什麼成本都太低，所以機幾乎乎就是cheap talk而以。

看來只有靠另一個管道才可行。我現在的問題變成是，網路上的真正的援交，他在別的管道下也找的道嗎? 例如，西門町，或是應召站?

Obama Land

我今天看到最令我驚訝的圖:

所以Obama不只是贏在黑人多的選區，他在以白人為主的地方也狂贏? 這怎麼解釋?

說法是，黑人很多或是很少的地方沒有種族問題，因此選民可以以政策做很理性的判斷。但是，難道黑人不多也不少的地方就有種族問題，而且就算有，他影響到Obama的選情?

這裡我覺得似乎有一些沒有辦法用黑白就能解釋的結果，可能要等一個比較完整的統計分析吧!

清大幫分享會：習慣力，4/7 Mon 19:00@活中101

這一次是我主辦，而且我也是講者之一。歡迎參加!

The Economics of Time Travel

This is an interesting blog post, and it is certainly entertaining to think through the implications. I love thinking about how this works:

If backward time travel is also somehow possible, maybe firms in the future will choose to outsource some of their operations to the past, locating their manufacturing and other services in lower-wage time periods.

Just to extend the analysis, if we applied comparative advantage to this analysis, we might think that certain time periods specializing in specific areas of production, which is what I thought initially. However, that might not be the case. The starkest case against this is that we bought wood from the past, and we sold them chain saws. This is reasonable, since we specialize in making chainsaws and our natural resources have depleted, and they have what we find valuable. Sounds good! But wait! The second they start preserving alot of trees, we might not be able to sell them chainsaws. That is if we bought natural resources from them, they would have less natural resources for R&D, which means technological progress might slow down in their time, which has an adverse effect on us. This is worth considering, but I think if we look at the margin, we can still get some trade going.

Thinking about this problem makes me think about technological progress. If we bought technology from the future, and in return, we sell them something (I can't think of anything), wouldn't every time period have the same production technology? In equilibrium, wouldn't technological advancements remain stagnant? As a result, a huge implication in cheap time travel is that the futre=past. The idea of time running, can be ignored.

Another, the implication of time travel is that the idea of uncertainty disappears. This may mean that money will indeed be neutral. However, the disappearance of uncertainty makes me more interested in the game theoretic aspects of competition and cooperation.

Repeated interactions make cooperation possible, whether it is infinite stages or finite stages (only needs a little bit of incomplete info on strategy space). However, the cooperation that appears in finitely repeated games may disappear, if both players knew about the type of strategy they have to work with. The player's type will most definitely reveal itself at the very end of the finite game, where a rational player will choose not to cooperate. As a result, cooperation might not occur in finitely repeated games, if both are rational. Also remember future=past, so the game we are playing in essense is a simultaneous game! So cooperation may never work in this case! Think about the prisoner's dilemma.

Imagine the US and USSR both had time machines, would the balance of terror work in this case? I imagine they would both have to be extremely nice people to avoid a war.

I don't know if I want to see that time machine built, to tell you the truth.

我阿扁錯了嗎 ? 我 阿扁錯了嗎 ?

If you are going to read this, please read the whole thing! Written by Anonymous

奉天承運，皇帝詔曰：

朕自千禧登基以來，挾政權轉移之威，立動搖國本之志，外拒三通，

內裂族群，期能千秋萬世，一統江湖。

無奈吾黨同儕未能同舟共濟，甚且黨同伐異，內鬥內行、外鬥外行，四人幫於是成焉，朕為之疾首！

頃又有三寶丟人於前、十一寇扯腿在後，為撫權力恐怖平衡，朕用心良苦：

宰相輪翻替換，唐、張、游、謝、蘇，除唐卿飛外，竟無一稱職！

惜唐卿非我族類、其心必異，哀哉！

加之內閣大學士遠哲，頭腦漿糊；
禮部尚書唐山，出言污穢；
刑部侍郎定南，不壽早夭；
監察御史岳生，年邁骨軟；
兵部光祿天羽，馬屁成精；
翰林院編修嘉文，尸位食祿；
澎湖金馬等邊關節度使，盡唱反調；
京畿之地九門提督，淪為藍營；
弘文館祭酒總監正勝，三隻小豬；
順耳府舍人志偉，獐頭鼠目；

正處燃眉之急，忽又蹦出一黃口楚子國榮，抱錯大腿信口雌黃。

嗚呼，天亡朕矣！

朕妻珍后，匱乏母儀，惹人生厭，然彼早年因朕成殘，朕愧之久矣。

及暮，彼愛金銀珠寶黃金美鈔，人之常情何能苛責？

事敗，彼拒不出庭，朕能奈何?

公主幸妤，性烈如母，嘗出言無狀，毀皇室形象！

然其尚能剛正自持，一幸也。

賊駙趙奴，攀龍附鳳，品德低劣，手腳骯髒，辱及皇室，朕已不認矣！

太子致中，寡言木訥，呆頭呆腦，不嗜國政，已遠走海外。

較之連逆、郝逆、宋逆、蔣逆等之後人，為父跨刀，克紹箕裘，朕深夜思之，一縷悽然、滿懷蕭瑟。

唉！生子當生孫仲謀！娶妻當娶‧‧‧，朕不願多言矣！

四年前子彈風波，幸賴奇美密醫遮掩在前，復靠昌鈺神探支吾於後，致使包圖龍再世，亦難斷矣！

此朕唯一堪足告慰於天者。

然朕之副舵秀蓮，極為難纏，斯時立朕身旁，知之甚詳，雖略遭魚池之殃，然早已無礙。
朕數度軟硬兼施欲杜其悠悠之口，然此刁婦視朕如無物，幾聲『嘿嘿嘿』，令朕如芒在背、毛骨悚然。

年前紅衫軍蟻聚於通衢，壞綱常、毀法紀、欺人心、凋經濟，朕恨之切齒！
其奪權之心可誅矣！

斯時也，朕懼通勤金鑾殿早朝，禍國者尤此為甚！

主其事者竟為本黨遺棄多年之敝屣，口口聲聲以創黨理想等言詞挑戰於朕，哼！

緣木求魚，目無國 君，朕對其惡之亟矣！

昔毛匪澤東大行之夕，病塌側呼小平告之曰： 『吾將去矣，惟黨內同志猶有不願隨君步伐而行者，吾憂之！』 小平曰：『東哥勿憂！凡不欲隨吾步伐者，吾令其隨你而行！』

嗚呼！朕亦將退矣，惟願隨朕而行者，疑僅蕭愛卿美琴一人耳，悲呼！

噫！吁！唏！

中原鼎沸、民不聊生，眾卿誤國，東倒西歪惟西瓜大邊是靠，彼等猶死不認錯，一意欲朕承擔，眾卿良心何在乎？公平乎？

昔杜卿正勝之先人曾云：『滅六國者，六國也，非秦也；族秦者，秦也，非天下也。』

此言繆矣！繆之極矣！

害朕者，眾卿也，非朕也；族朕者，天下也，非朕自己也！

嗟夫！

每念及此，思之悽哽，吾何罪之有、吾何罪之有？
(我阿扁錯了嗎 ? 我 阿扁錯了嗎 ?）欽此！」

Low Probability Event

P[我有勇氣跟一個完全陌生的女生(denote as A)說我覺得他很漂亮 given 我沒有喝醉]=0.03

P[我挑到A given A漂亮]=0.01

P[A不理我]=1

P[我去胖達喝飲料 given 我喜歡Starbucks!]= 0.005

P[有女生跟我一起喝飲料女生(denote as B)]=0.25 (我沒有故意 inflate 這個機率)

P[A在那個時候在胖達消費] <1

P[B認識A] < 0.5

=> max prob of all this happening = 0.0000001875

最牛逼博士論文

From PTT Econ:

1、最牛逼博士論文就是在還沒答辯之前已經發表在最好的期刊上，而且鑒於論文很長，該期刊必須像小說一樣連載。實例：張五常博士論文《佃農理論》，當年在JLE上連載四期。

2、最牛逼博士論文答辯就是答辯人一直在挑戰答辯委員會成員，直到問的這些教授們緊張到恍惚以為自己才是答辯人。實例：薩繆爾森的博士論文答辯結束後，答辯委員會成員之一的熊彼特（上世紀最偉大的經濟學家之一）轉過頭去問另一位成員里昂剔夫（諾獎得主）：“瓦西裡，我們通過了麼？”

3、最牛逼投稿論文就是讓編輯滿世界都找不到一個能看懂這篇論文的匿名審稿人，最後只能發表，根本不需要修改的。實例：SIMS1971年發表在《數理統計年鑒》上的論文《無窮維參數空間中的分佈滯後估計》。SIMS寫完這篇論文後沒投經濟學雜誌，因為他顯然知道沒人看的懂。於是投給了最牛逼的數理統計雜誌，結果編輯死活找不到審稿人，最後好不容易湊合拉來一個，審稿報告是這麼寫的：“我真的不明白這篇論文在說什麼，但是我檢驗了其中的幾個定理，好像是對的。所以我猜應該發表。”

Best Speech I have Heard in Years

A More Perfect Union

一橋大學

很多人問我我去日本哪裡。

我主要是去一橋大學。這一所學校只有四個領域: 商，法，經濟及社會科學。所以他非常小，但是整個校園走起來很舒服。他在經濟學領域也是表現得不錯。

下面是我在國立照的校園照片。

這條路到了四月初時，櫻花卉盛開，聽說許多日本人會跑來觀賞。

校內:

Day 2: Gibbons Lecture - Agency Theory in Organizations

The economics literature has long attributed the problems inside of firms to information asymmetry, more specifically ‘hidden actions.’ The principal can not observe the actions of the agent, but can only observe the output, which has noise. The agent proceeds to provide sub-optimal effort levels. This is the classic moral hazard problem. There are three caveats here. One, output production has noise, so our principal can not deduce with certainty the agent’s effort level from output. Second, our principal can contract perfectly on output, so our principal can do everything in his power to create enough incentives through contracts to preempt a shirking worker. Thirdly, our agent has to be risk averse. As a result, our principal’s problem is to write a contract that creates enough incentives for the agent to work hard, while still providing enough insurance for the agent.

However, with the concept of non-contractibles creeping into economics, we are provided with a new option in modeling agency problems. While moral hazard is a serious and authentic problem inside firms, we can not help but wonder how much managers or firm owners think about risks when drawing contracts. Instead, an agency problem can arise simply because the principal is paying for the wrong things. For example, let us assume that a firm is concerned with its output quantity and quality. However, quality is not contractible. As a result, the firm contracts solely on quantity, then the worker is provided with full incentives to boost quantity, all the while ignoring the products’ quality. This is the so called ‘getting what you pay for problem.’ In short, the principal can not align the interests of the agents with their own, simply because the things the principal care about can not be included in the contract. We shall call contracts of these types ‘formal contracts.’ Their key feature is that the firms choose to contract on objective and measurable aspects which are verifiable in court, but often a misalignment of interests arise. Such multi-task models where only a portion of those tasks are contractible were developed by Holmstrom and Milgrom (1991) and Baker (2002).

There is a solution to non-contractibles though. Continuing our example of quantity and quality, a firm can promise in advance to award the worker a bonus if he also produces high quality output. Since quality is not verifiable outside of the relationship, the principal has an incentive to back out of his initial promise. However, a contract such as this could be sustained in the long-run, where the worker chooses to produce high quality output and the principal pays a bonus in every period. In other words, such ‘relational contracts’ are strongly dependent on the likelihood of the principal and agent’s continuous cooperation. If the likelihood of continuous cooperation is high, then a relational contract is much more likely to be sustained. The concept of relational contract was formally introduced by Bull (1987) and then further advanced by Levin (2003).

As you can see, I did not summarize the models that Gibbons introduced. I have written them down somewhere though.

Day 2: Gibbons Lecture - Introduction

“Firms don’t have preferences, people do!” – Robert Gibbons

Before 1937, firms have long been treated as a black box in economics. Economists were well aware of the differences between a firm and a person. People consumed, firms produced. People maximized utility, while firms maximized profits. The standard theory in economics laid foundations, so that economists can build models representing intricate details in their interactions, between people, between firms, or between people and firms. However, the literature on firms ends there. There were no investigations on the interactions within firms, or on contracts. Economists didn’t even ask why there were firms in the first place! Firms looked like ordinary ‘individuals’, except they produce instead of consume, and maximized profits instead of maximizing utility. That changed until Coase’s seminal paper in 1937.

Coase asked a simple question, which would send a ripple through economics. I say ripple, because it would take a little more than 30 years before his ideas caught fire. He asked why were there firms to begin with? In a world where Adam Smith’s invisible hand automatically guided resource allocation to their most optimal use, it seemed curious that some (or most) production had to be conducted within a firm. Why not just organize production within the market? Coase offered us a simple, yet intriguing answer to this question, so intriguing was the answer that it took more than 30 years for economists to take a serious consideration in Coase’s ideas. Coase told us that using the market entails a cost, he called a ‘the cost of using the market.’ It would be 30 years later, when Stiglitz named this cost ‘transaction cost.’

It didn’t take long after the 1960’s for transaction cost economics to catch a momentous boost in economic literature. Economists such as Oliver Williamson, Benjamin Klein directed their research towards finding formalizable theories of the firm. It would not take long after that for economists to finally study the interaction within firms, thanks to the advent of game theory, agency problems could be analyzed and optimal incentive contracts could be formulated. However, something was missing. Our theories seemed so alien to real managers in real firms that every working economists knew that the field is still in search for a realistic theory of the firm. In this chapter, we will discuss the classical agency problem framed in terms of the incentive – insurance tradeoff, and the new method in explaining agency problems, non - contractibles.

Also, in this chapter, we will discuss the existing theories on the boundary of the firm. This area is budding with research literature, which started with Oliver Williamson and Benjamin Klein, later advanced by Gene Grossman, Oliver Hart, and John Moore. We will discuss the similarities and the differences surrounding their theories, and briefly discuss the empirical work.

1.1 What are Firms?

Firm behavior can not be dissected until we can fully appreciate the complex relationship inside firms. Economists used to share the view that firms are ‘clean,’ ‘well organized,’ ‘powerful’ production entities. Decision and its relevant information will be gathered, analyzed, processed and finally utilized to their utmost value, producing output that can fully capture the firm’s underlying potential and maximize profits without any complications. However, this view of firms and organizations is wrong.

The description we gave above can certainly describe a single person. On the other hand firms are made of numerous employees, managers and owners. In other words, there are political games that go on inside firms. These potentially damaging behaviors inside and between firms will determine the boundary of firms, and the incentive contracts inside firms. Agency theory equips us with the knowledge to tackle and explain a wide ranging phenomenon exhibited by firms. But before we move on to the agency problem, we have to answer this question: If there are dirty politics and inefficient behavior within firms, why are there firms in the first place?

Coase introduced to us the concept of transaction costs. If transaction costs are high, the market system fails to allocate resources efficiently. In other words, the price system fails, as transaction difficulty rises. As a result, firms exist because operation with in an organization, in some cases, is less costly than operating in the market system. So even though empirical evidence shows us that firms are ‘systematically stupid,’ performing worse than markets efficiency wise, we could be merely witnessing a case of selection bias.

From the graph above, we can see that the firms we observe, operate in an environment where the transaction difficulty is greater than While the markets we observe, operate in an environment where the transaction difficulty is less than . More interestingly, we would find the markets operating on a higher efficiency level than the markets. But this is in no means evidence against the effectiveness of firms or organizations in general. Theory suggests a difficulty in comparing these two in an empirical setting since we would encounter a selection bias problem. To sum it up, firms deal with hard problems that the markets couldn’t handle. We are now ready to discuss the workings inside a firm.


As you can see, I'm trying to organize my summary into maybe a small book.

Day 4: Moving Around

第四天在日本，今天不上課，所以表示我可以到處逛一逛。我的日本朋友 Ryo Kawasaki 跟 Shin Kishimoto 帶我逛東京。買一張710日圓的東京地鐵通一日票，就開始當觀光客了。我很討厭當觀光客，尤其是一直照相，看起來很蠢。但是這一次旅行，我照了很多照片，因為我的忠實讀者想看。所以，我現在就跟各位分享一些照片，及簡單介紹他的內容跟故事。

Senso-ji Temple (浅草寺)
我們第一站到 Asakusa Station，去淺草寺。首先跟各位介紹一下日本的宗教信仰。日本有兩種盛行的宗教: "佛教" 及 "Shinto (神道)"。淺草寺是佛教的，而我星期天去的明治神宮是神道的。當初，唐朝我們中國人將佛教引入日本，引起當時的日本人熱烈的迴響。原因很簡單，日本的神道沒有講關於人死後的事情 (after-life)。然而，佛教裡的 after-life 描繪得相當清楚，所以最後日本將兩個叫互相結合。因此你在路上隨便抓一個日本人問他是什麼教，90%會跟你講神道，而85%會跟你講佛教，所以很多是兩者都信的。然而，還是有許多不同處。例如，一般的佛教的廟會拜神像，但是神道多半會拜大自然，因此明治神宮的周圍的樹木就是人工林。


我和 Shin Kishimoto。


我和 Ryo Kawasaki。


個位有沒有發現，這有五層，每一層代表了日本深受佛教影響的五個元素: 地，風，火，水，空。


我抽了籤，上面寫 "凶"。最差的籤。奇怪的事我當時籤筒怎麼倒都倒不出籤，後來到初 "83" 一看這張紙條寫的，我趕緊去買護身符。希望運是可以改善。期實，把籤綁在那裏應該就可以將壞運給留在那。(最後得知: 淺草寺有60%是最壞的籤)



話說這個煙可以治病，你希望變聰明就讓煙薰一下頭。照理來講，煙是要花錢買的，但是他有嚴重的 free rider 問題，所以我猛薰免費的煙。(記住，我剛剛才抽到一張說我會病一整年的籤)



這裡可以清洗你的靈魂。先用右手將瓢子裡的水洗左手，再用左手洗右手，最後再用水清洗嘴。很多人喝下去了，我沒有，但是現在回想抽到那籤後，應該喝下去的。

在 Asakusa 站外面，可以看到 Asahi 飲料的公司總部:

當時設計是讓那金黃色的東西站立的，但是因為擔心會有安全問題，所以現在看起來像 "金子"。

我們還去了 Akihabara，但是因為星期三 Cosplay 那一些人還沒有出沒，所以沒有特別好玩。我們到是有去一家咖啡館，裡面的服務生都打扮成傭人，裙子很短，女生也蠻可愛的。不好意思，我沒照相。我星期天又去了一次 Akihabara，照了一些 cosplay 的。

Tokyo Tower (東京鐵塔)
很多人說，日本人很會模仿跟抄襲，東京鐵塔是一個很好的例子。他看起來就像巴黎的 Eiffel Tower，那是因為他的靈感就是從那裏來的。而他又比 Eiffel Tower 更高，又更輕。他們真的鰻會模仿的，但是最後弄得比你好。他是橘白相間的是因為飛安的考量。

從東京鐵塔看到的 Rainbow Bridge。他連結到了 Odaibo。若天氣好的話可以從東京鐵塔看到富士山，但是當天雲層太低。

我下一篇在跟各位分享我星期六去新宿玩的一些照片跟感想。

Day 3: Ominous Meeting

我先聲明，我到時候會開始整理上課的東西，但是先寫一些有趣的事。

我星期二晚上，在上野逛街，走到一個小巷裡，小巷似乎很多小館可以吃東西，但是更引起我注意的事一群穿著黑色的大衣及西裝，髮型挺酷的，站在小巷的兩旁，每走四步就有一個。他們也是我第一次發現日本人在街上吐痰。我走一走發現，跟我一起走進巷子裡的人都不見了，所以我也就趕快轉到另一個地方。過不久後，我就發現一群警察往那邊跑。

我回到房間問我的日本朋友，那一些人是誰? 他說極有可能是 Yakuza。

才第三天就看到日本世界有名的黑幫。

Day 1: Arrival

這我第一次自己出國。

我去過很多地方，但是這一次是我第一次自己出國。幸好我的第一次是在日本! 因為日本所有東西都標示的很清楚，所以做車轉車都沒有問題。但是，若沒有來過，一定會很緊張，因為那鐵路線簡直就像蜘蛛網，密密麻麻的。又怕語言不通，什麼事都做不了，但是還好寫中文他們看得懂，所以一覺得開始雞同鴨講實，馬上拿紙筆出來寫中文，他們就開始: "Ah! sodesgane!" 更重要的是他們都很熱心。

我從成田機場出來時，有兩種車可以到上野: skyliner 或 limited express。兩個都是同一個線上

的，skyliner 要將近 2000 yen，而 limited express 只要1000 yen。但是limited express 大約慢個 20~30分鐘。因此我選擇了便宜的，但是這是對的選擇也是錯的選擇。錯是因為 skyliner 有指定座位，而limited express 沒有。我在terminal 2上車，所以車 上已經坐滿了人，但是沒有關係，因為過了兩站就有兩個人下車。正當我要做下去的時候，有三個婆婆上車，我發現都沒有人讓位，我就站起來讓位給他們 。(我發現，好像都只有我再讓位置給老人，每一天做都只有我。)

這一讓就不妙了，因為之後的站都沒有人下車。上野剛剛好是最後一站，而我就在那邊站了將近一個小時。直到做到接近倒數幾站時，才有人開始下車，我才有位置坐。

那為何坐對車呢? 因為同一個車廂上有一位很漂亮的女生。後來我終於有位置坐時，他就坐我旁邊，而坐我們對面有一個男的一直在打PSP，打得目不轉睛，他後來偷看了那個女的一眼，之後就沒有專心打PSP了，每打五秒就偷看一眼。

日本東西真的很貴! 想吃一頓好東西就要花一點錢，而當你看到便宜的東西時，你就會發現被騙，因為實際的東西比圖片上來的小太多!

Destination: Japan

Leaving for Japan tomorrow.

Level-k Thinking: New modeling possibilities?

有趣的觀點:

Consider a game where everyone in a classroom picks a number between 0 and 100. The person closest to half the average wins.

Obviously, picking a number over 50 would be silly. Based on this, picking a number over 25 would be silly. Similarly, picking a number over 12.5 would be silly. Continuing this line of thought, picking any number other than 0 would be silly. These thoughts show the level of thinking of those involved, from level-1 to level-infinity.

Level-k thinking analyzes such games. In actual experiments, players never pick 0, which would be suggested by a Nash equilibrium. Instead, they utilize many different levels of thinking.

使用 Level-k 來 model 不外乎就是讓均衡符合實際的狀況。但是他有一個很強的假設，level-2 的 player 一定要假設他認為其他的 player 是 level-1 或更低，他不能認為有其他 player 是 level-3 或以上的。因為若他認為有人是 level-3，則理性的他，就不再是 level-2 了。

所以為了讓結果更符合實際狀況，level-k thinking 使用了同樣不合理的假設。

Good Book: The Logic of Life - Uncovering the New Economics of Everything

我只有讀第一章，但是已經馬上愛上 Tim Harford 的文筆了。

第一章，Harford 就解釋為何經濟學是一個很好的工具。念經濟學的人，念到最後會時常對這科目失去信心，不相信自己念的東西。然而，Harford 這本書是試圖說服大眾經濟思維裡的 "理性" 的強大力量，他同時也讓我重新找回對這科目的興趣。他寫道:

Does this mean that rational choice theory is as much use as flat earth theory? No. It's more like a perfectly spherical earth theory. The earth isn't a perfect sphere, as anyone who has climbed Mount Everest will tell you. But it's nearly a sphere, and for many purposes, the simplification that the earth is spherical will do nicely.

歐巴馬的經濟智囊團

From

Like Bill Clinton in 1992, Obama's campaign boasts a cadre of credentialed achievers. Intellectually, however, the Obamanauts couldn't be more different. Clinton delighted in surrounding himself with big-think public intellectuals--like economics commentator Robert Reich and political philosopher Bill Galston. You'd be hard-pressed to find a political philosopher in Obama's inner wonk-dom. His is dominated by a group of first-rate economists, beginning with Goolsbee, one of the profession's most respected tax experts. A Harvard economist named Jeff Liebman has been influential in helping Obama think through budget and retirement issues; another, David Cutler, helped shape his views on health care. Goolsbee, in particular, is an almost unprecedented figure in Democratic politics: an academic economist with a top campaign position and the candidate's ear.

可以從台灣身上學的寶貴經驗

今天早上在德州上演了一場對決: Obama vs. Clinton 的辯論

我個人認為Obama四平八穩，有領導者的風範，而Clinton的表現也非常有風度，雖然落後但是仍然很有風度 (不像台灣的政治人物)。但是很顯然的Clinton很想強調自己的健保提案比Obama的更好。而觀察家竟然一致同意，Clinton的確在健保上勝Obama。

But it was by no means a poor performance for Clinton, and she did successfully draw some contrasts with Obama on his health care stance — an issue in which she holds the upper hand. Obama's plan could leave many uninsured, and Clinton effectively stressed this point in one of her strongest moments of the debate. She immediately put Obama on the defensive about his own plan and proved she understands this issue through and through.

????!!!!!!

這太可笑了! Clinton的健保是一個mandante。也就是所有的人都要購買健保，不購買者會被罰錢的! 但是Obama是降低價格好讓大家都有機會享有健保。一個是有選擇餘地的，另一個是被逼迫的，你要哪一種!?

Clinton的政策不只違反經濟sense，也違反了美國建國的精神!

只是一場選舉

Great Piece!

This election is certainly important. But based on the historical record, it isn’t likely to result in a major swing in economic policy. Fundamentally, democracy is not a finely tuned mechanism that can be used to direct economic policy as a lever might lift a pulley. The connection between what voters want, or think they want, and what ultimately happens in the economy, is far less direct.

.....THAT might sound pessimistic, but it’s not. Many Americans will be living longer, finding new sources of learning and recreation, creating more rewarding jobs, striking up new loves and friendships, and, yes, earning more money. Just don’t expect most of these gains to come out of the voting booth or, for that matter, Washington.

這是在講美國的選舉。但是廣義而言這也可以當成今年所有面臨抉擇的選民所必須面對的事實，其實，你今年選誰對你的影響其實是有限的。

Wisdom of the Crowd

Terrific website!

以後有什麼國際大事應該參考這個! 不知道什麼時候會放台灣大選的預測?

ps. 看樣子，Obama 極有可能被民主黨提名! Which is great!

Pedal to the Metal: What happens when signals change

上星期有一則新聞:

在紅綠燈上加裝倒數計時器日漸普及，但交通部運輸研究所的報告指出，加裝綠燈倒數器的路口肇事件數比設置前多一倍，加裝紅燈倒數器則減少一半，兩者兼有的路口肇事件數增加一九％。運研所建議，儘速拆除綠燈倒數計時器，或關閉功能。

這個跟 prospect theory 下的 loss aversion 有沒有關係? 我個人覺得有。

我猜想(也希望)若期望理論的基礎能更穩固，他能解釋更多元的人類行為，也能帶給個經一些新的刺激。

老虎伍茲 vs. 其他選手: 其他選手會變弱?

答案是:會!

簡單來講，老虎伍茲太強了!所以搞的其他選手都沒有誘因好好打。

What Every Economics Lecture Should be Like

Steven Levitt 寫說他有一次請了一位特別來賓到他的課堂上:

I brought in a very high-priced call girl to guest lecture at my undergraduate
Economics of Crime class.

那堂課的評價呢?:

The next day, I asked my students whether they liked the lecture. More than one-third of them said it was the single best lecture they had attended in their
four years of college. I had to agree with them.

話說那一堂課有一些有趣的對話:

One of his research subjects is a former computer programmer who charges $300 an hour as a high-end call girl. Levitt asked her if she was happy when her “client line” rang on her Palm Pilot. She told him that she wasn’t happy, but indifferent. He told her that meant she was not charging enough for her services. Later,Levitt offered to pay her the hourly rate she charged clients if she would come speak to his economics class. He was surprised, however,when one of the students asked the prostitute what she charged and she replied, “$400 an hour.” The student then asked her how she had determined that rate. “She turned to me,” Levitt recalled, “flashed me this huge smile and said, ‘Well, I was talking with Professor Levitt and he convinced me that my services were worth more than I was previously charging.

研究生的態度

我今天看到的一句話:

By grad school, students know the drill cold: read assignments, hear lectures, do homework, and spit it all back on the exam. Problem is, just then the game changes from grades to papers; few will care about your grades, compared to your research papers, written and published. A research paper is not a term paper, and can't be dashed off the weekend before it is due. A research paper does not offer a broad overview; it says something specific and new, even if minor, that fits in a context of other research papers.

看到這一句很感動! 因為上一學期的實變把我搞瘋了，不但被當 (人生第一次被當) 也影響到我其他科目的表現，因為花太多時間在那上面導致我很多經濟的課都是臨時抱佛腳。

結論: 用心在研究上是研究生的職責!

Good Economics vs. Bad Economics

我想最近大家可能都忙著想一些新鮮的題目，試圖尋找自己的經濟見解。但是，若你像我，時常胡思亂想，將一堆學過的東西串在一起，最後發現整個邏輯很勉強，甚至到最後連自己都無法說服時，你可能就是一開始就是錯的。所以有沒有什麼方法可以一開始就檢視自己的理論是不是對的呢?

我最近在讀一本書，名叫 "Discover Your Inner Economist - Use Incentives to Fall in Love, Survive Your Next Meeting, and Motivate Your Dentist." 這一本書是 Tyler Cowen 所寫的，所以喜歡閱讀他的部落格的人會覺得他所引用的例子或故事相當熟。他在第一章有提到說要如何辨認 Good Economics 或 Bad Economics 的方法，我認為這方法非常適合大家，例如學生或做研究的人，在此跟大家分享:

1. The Postcard Test: 你的理論的概要必須在一張小卡片上就能闡述清楚了。

2. The Grandma Test: 你的奶奶必須能夠聽懂你的理論。

3. The Aha Test: 你的奶奶聽完你的理論後必須要有一點驚喜感，最後要點點頭說: "有道理!"

若你的理論無法做到這三點，你的理論就可能太複雜，也很可能就是錯的。

Jp-Tw Contract Theory Conference

我昨天 (12/8) 跑去中研院參加 Contract Theory 的研討會。這個研討會說起來挺有趣的，因為日本自己每一個都定期來一個Contract Theory Workshop。(Relevant Information: here and here。) 但是這一次來台灣跟咱們聚一聚，一起腦力激盪。

昨天學到相當多的東西，大部分在於如何問問題。昨天許多問題與建議我覺得都非常好。我也覺得我應該加強這一點，參加了那麼多研討會，總覺得自己得直覺反應不夠快，但是有再進步，畢竟我也發現許多提出來的問題，也是我心中的疑問。

但是重頭戲在晚上! 我帶著我朋友，邱哲良，一起跟他們吃飯。一到餐館發現，有四張桌仔，而有人問起: "哪一張是主桌?" 我就看到服務小姐，指著窗旁角落的桌子。而我也看到周嗣文，蔡崇聖，周瑞賢，我們清大的老師都坐在那裡，我也有一股衝動想坐在那裡，但是聽說是主桌就自己找了一桌坐。沒有想到，盡然有兩個日本人跑來跟我們坐，所以我就展現我的熱情開始跟做我左邊的日本人聊天。我問他叫什麼名子，他就把他的名牌秀出來給我看，我一看到我就知道我做錯桌子了，上面寫著 Hiroshi Osano，是這一次的 oraganizer 之一，正當我心中開始有一股涼意時，我看到陳恭平老師也跑來，坐在Osano的旁邊，那時是我這冬季以來第一次感到寒冷。但是，沒有關係，因為其他坐在那一桌的台灣同胞，都以為我們是日本人，所以陳恭平老師還用英文到酒給我喝，我也喝了，身子也暖起來了。最後發現我會中文，才知道我只是一個台灣的小毛頭。

整個晚餐氣份很好，那一些日本人很好聊，他們對台灣的吃的很有興趣，而我也對日本的文化有一點興趣，昨天聊了很多有關皇室的事情，因為作在邱哲良旁的Shinsuke Kambe在皇室成立的大學教書。他們也對我的手機感到興趣，他們覺得太小了! 很好玩!

後來我的老師又帶大家去喝酒，我也就跟著去了，最後喝的醉醺醺的，不知東南西北，只好跟著邱哲良到他的家去過夜。以後不能喝太多酒!

Nobel Prize in Economics 2007

Goes to Leo Hurwicz, Eric Maskin, and Roger Myerson, "for having laid the foundations of mechanism design theory."

這是我 之前 (現在??) 很有興趣的領域，機制設計。這領域數學能力要有一定的基礎，頭腦要非常清楚。

我今年初有去聽 Eric Maskin 在台大舉辦兩天的講習，教導大家基本的機制設計的觀念。他給我應向非常深刻，他用淺顯易懂的例子就將我在論文上看不懂的東西給解釋清楚了! 超強!

所以說，我也是有被諾貝爾獎得主教過的人。

More on this later this week.

Economics Nobel Predictor 2007: Part 2

The odds at Ladbrokes.

Helpman and Grossman 仍然是 favorites! 但是 Bhagwati 的名子竟然沒有在上面。

悲亢的詩 (北島)

〈回答〉──北島

卑鄙是卑鄙者的通行證，
高尚是高尚者的墓誌銘。
看吧，在那鍍金的天空中，
飄滿了死者彎曲的倒影。
冰川紀過去了，
為什麼到處都是冰淩？
好望角發現了，
為什麼死海裏千帆相競？
我來到這個世界上，
只帶著紙、繩索和身影，
為了在審判之前，宣讀那些被判決的聲音：
告訴你吧，世界
我－不－相－信！
縱使你腳下有一千名挑戰者，
那就把我算作第一千零一名。
我不相信天是藍的；
我不相信雷的回聲；
我不相信夢是假的；
我不相信死無報應。
如果海洋註定要決堤，
就讓所有的苦水都注入我心中；
如果陸地註定要上升，
就讓人類重新選擇生存的峰頂。
新的轉機和閃閃星斗，
正在綴滿沒有遮攔的天空，
那是五千年的象形文字，
那是未來人們凝視的眼睛。

The Conflict between an Economist and an Economic Man

我長期以來都覺得經濟學裡的模型將人假設的太"聰明"。但是，經濟學家又認為當這一些人表現的不"聰明"的話就表示他不"理性"。所以理性到底是什麼? 而經濟學家又真得很理性嗎? 下面的故事是 Harry Markowitz (1990年諾貝爾獎得主，CAPM的始祖) 在做投資時的趣事:

"There is a story in the book about Harry Markowitz,” Mr. Zweig said the other day. He was referring to Harry M. Markowitz, the renowned economist who shared a Nobel for helping found modern portfolio theory — and proving the importance of diversification. It’s a story that says everything about how most of us act when it comes to investing. Mr. Markowitz was then working at the RAND Corporation and trying to figure out how to allocate his retirement account. He knew what he should do: “I should have computed the historical co-variances of the asset classes and drawn an efficient frontier.” (That’s efficient-market talk for draining as much risk as possible out of his portfolio.)

But, he said, “I visualized my grief if the stock market went way up and I wasn’t in it — or if it went way down and I was completely in it. So I split my contributions 50/50 between stocks and bonds.” As Mr. Zweig notes dryly, Mr. Markowitz had proved “incapable of applying” his breakthrough theory to his own money. Economists in his day believed powerfully in the concept of “economic man”— the theory that people always acted in their own best self-interest. Yet Mr. Markowitz, famous economist though he was, was clearly not an example of economic man.

所以若這麼天才的經濟學家都無法依照他自己所創的模型做投資決定，我們憑什麼認為現在的經濟學沒有什麼 "重大" 的問題。我個人認為經濟學有很嚴重的問題，需要更新的方法解決。實驗 anyone?

Economics Nobel Predictor 2007: Part 1

九月快結束了! 而十月中，就要公布諾貝爾經濟學獎的得主。有哪一些人有機會得呢?

Thomson Scientific 預測今年這幾位經濟學家有機會:

Elhanan Helpman Galen L. Stone Professor of International Trade Harvard University Cambridge, Mass., USA Emeritus Professor Department of
Economics Tel Aviv University, Israel
-and-
Gene M. Grossman Jacob Viner Professor of International Economics Princeton University Princeton, N.J., USA Professor, Department of Economics Woodrow Wilson School of Public and International Affairs Princeton, N.J., USA
For their contributions to international trade and economic growth.

Robert B. Wilson Adams Distinguished Professor of Management Emeritus Stanford Graduate School of Business Stanford University Stanford, Calif., USA
-and-
Paul R. Milgrom Shirley and Leonard Ely Professor of Humanities, Department of Economics Stanford University Stanford, Calif., USA
For their work, both theoretical and practical, on the mechanism of auctions.

Jean Tirole Scientific Director, Institute of Industrial Economics University of Social Sciences Toulouse, France Affiliated research member of CERAS Paris, France For his research in industrial organization and regulation.

我認為這幾位經濟學家都應得獎，但是應該不是今年得。例如，Jean Tirole 在 industrial organization 跟 contract theory 上有卓越的貢獻，但是論得獎還早了一點。而 Milgrom 與 Wilson 若要拿獎，很難不包含 Krebs 跟 Roberts，號稱 "The gang of four." Helpman 也一樣，講到 international trade，很難想像 Bhagwati 還沒有拿到，所以 Helpman 可能還太早 (不然就是一起得)。

從今天起我每幾天，都會介紹一位我認為有機會得獎的經濟學家。

排隊理論: Part 1 of 2

為何大家要排隊?

排隊是一件非常沒有效率的事情，就拿飲水機來說: 排隊是按照每一個人到來的順序，而不是每一個人的口渴程度排序。因此當一位散步到飲水機喝水的人排在剛跑完4000m的人的前面時，這種結果就很沒有效率。於是就有經濟學家想一個解決這件事的方式，而這個答案非常直接也很簡單，賣位置。

那一位散步而來的人可以將他的位置賣給剛剛跑完的人。其實，這種行為很常見，我們都稱這些人 "黃牛" (我之前有賣過黃牛票，不好賺!)。但是為何不是所有的排隊都可以用此方式解決呢? 有幾個可能的原因:

1. 買票跟排隊喝水只差在，買票可以依次買很多票，而喝水只能一次一個人喝。所以那一位散步的人只能賣給一個口渴的跑者，而那一位賣黃牛的人可以賣給許多個買家。但是占一次位置的fixed cost 很高，只賣給一個人是無法cover的。

2. 若將位置賣給口渴的人，其他位置的人可能會提出更低的價格，最後結果就像 Bertrand competition 一樣。其實我強烈質疑販賣黃牛票的非法性，因為按照一般的分析結果會發現，若販賣黃牛票合法化，會有許多賣家加入，將利潤降到0，因此買黃牛票的人只是沒有時間排隊而已，也不會因此而負更多錢，而原賣家(例如主辦單位)也不會怕黃牛將票價提高。所以禁止販賣黃牛票似乎是道德問題，而非經濟問題。

現在目前的方式雖然很沒有效率但是，大家所提出的解決辦法也都難以實行。我最近閱讀到一個非常特別的解決方式，下一次跟各位分享。

有人看我的部落閣

一位大陸網友 (我不認識)，有看過我的部落閣。

我怎麼知道? 在他的部落格裡，最右邊有一欄為 "形形色色"。請問第一個 link 是什麼?

左右腦

請問上面這個女的旋轉方向為何? (要點一下圖片)

若你看到的為順時鐘，則你的右腦比左腦發達。

若你看到的為逆時鐘，則你的左腦比右腦發達。

若你依開始看到的是逆時鐘，而後突然變為順時鐘，則你的IQ有可能超過160!!

很有趣吧!

The Essential Math

這些是想當經濟學家的必修數學課程 suggested by Greg Mankiw:

Calculus
Linear Algebra
Multivariable Calculus
Real Analysis
Probability Theory
Mathematical Statistics
Game Theory
Differential Equations

我只差 probability theory, and differential equations. 現在正在修real analysis. 這也是為何我最近都沒有寫文章. 因為每星期都有作業!!

More Sex $969

我前幾天去書店買書，書名叫 More Sex Is Safer Sex: The Unconventional Wisdom of Economics. 標題非常聳動!

結帳時，條碼一刷，螢幕卻顯示: MORE SEX $969。That is pretty cheap!

Profile of Robert Barro

The Profile. Still reading it, but this sentence struck me:

It would have been difficult to predict this outcome [of his success in economics] from the title of Barro's first publication in 1970: "The Crystal Structure of a Dimeric Cobalt Compound Containing a Chloro Bridge."

為何Barro沒有繼續研究物理呢?

"Feynman was a great inspiration, but what he taught was often way above my head. It made me realize I wouldn't be close to the top in those fields."

我國中時也非常迷物理，也是被Feynman的書吸引住了。當時我看了他的自傳 Surely You're Joking Mr. Feynman, 至近對我的影響仍然很大，因為是那ㄧ本書讓我對學者的印像改觀。後來在師大附中唸高中時，才發現物理=霧裡。我雖然成績在班上不錯，但是我知道若我繼續追隨當物理學家的夢，我對人類知識的貢獻是非常有限的。我的目標一直是想要有一點貢獻。

A Great Loss: Luciano Pavarotti passes away at the age of 71

The News.

這位歌劇巨星因為胰臟癌去逝。我的阿姨十年前也因為胰臟癌去逝。有醫生說過，胰臟癌末期的病患很難活超過八個月。

我記得我第一次聽到Pavarotti唱歌是我幼稚園的時候。我當時還住在紐約，而紐約的公共電視非常喜歡播放 "三大男高音" 的表演。我記得我被他們的聲音深深的感動，甚至在洗澡間，邊洗邊模仿。

這非常有趣:

.....what appears to have been a normal childhood with a typical interest in sports — in Pavarotti's case soccer above all — he graduated from the Schola Magistrale and faced the dilemma of a career choice. He was interested in pursuing a career as a professional soccer player, but his mother convinced him to train as a teacher. He subsequently taught in an elementary school for two years but finally allowed his interest in music to win out.

During his years of study Pavarotti held part-time jobs in order to help sustain himself — first as an elementary school teacher and then, when he failed at that, as an insurance salesman.

我們應該很慶幸，他選擇了音樂這條路!

Fun Facts About CEO and Firm Value

From recent studies:

[Firm's Value] slid by about one-fifth, on average, in the two years after the death of a CEO's child, and by about 15% after the death of a spouse. As for an executive's mother-in-law, the old jokes seem to hold: The researchers found that profitability, on average, rose slightly after her demise.

非常有趣!

Prediction Tools

非常好玩! 我發現平均而言我可以活到82歲。

還有其餘的一些網站都在這網頁。

The Existence of Hierarchies

目前大部分的經濟理論都無法完善的解釋公司內部的結構，尤其是謂何會有階層的現象 (老闆，經哩，員工)。有一些公司大到階層超過幾十個!! (我之前有blog過hierarchies)

目前再實證上也無法確切的橫樑一家公司的 "身高"。因此再這方面的時正研究很少，而有做此研究的經濟學家都是使用顧問公司所提共的資料。這有許多問題。第一，資料很貴。第二，資料所有權是顧問公司的所以無法像其他學者分享。第三，公司有幾個階層的定義很難決定，任何資料都將有爭議。

實證的問題我們先不提，就連理論的問題都很難解決。而目前較popular的模型是中國的經濟學家，錢穎一所提出的。(Link to paper: INCENTIVES AND LOSS OF CONTROL IN AN OPTIMAL HIERARCHY) 今天先就簡單介紹一下吧!

錢穎一的主軸是 moral hazard (道德風險) 跟喪失控制能力 (loss of control)。先講moral hazard的部份。假設今天有一位老闆，雇用了20位員工，但是老闆沒有辦法隨時隨地都看著他們工作，因此員工就有偷懶的頃向。假設老闆只能抽一位員工來檢視，因此每一位員工有1/20的機會被老板檢查，員工偷懶的情況稍微改善了，但是能更好嗎? 今天老闆能在僱用4個經理人，而每一個經理管5個人，所以每一個員工有1/5的機會被經理檢查，因此員工的偷懶狀況大大的改善了，員工出力也變多。那老板呢? 只要監視這4位經理就好了ㄚ! 因此每一位經理有1/4的機會被老闆盯。而一個職員管理的人數就稱做為 span of control (控制範圍)。

那麼若加一個層級這麼好，我們家無數多個就好啦! 但是經濟學上有一個現象較loss of control。這最早是Williamson所提出的。他的意思是越多層級的公司，最下面一層的員工，每一位所能生產的量會下降。這個現象的力量是從哪來也不清楚，但是想一想還蠻合理的。因此家越多層級，最下面一層的maximum生產量就會下降。因此老闆的問題就是在span of control跟 loss of control之間做最適化。

以下是一個較technical的簡介:

500 Years of Female Faces in Art

Amazing video! Link

Q&A: 台灣英文菜嗎?

今天新聞都在報導最新出爐的 TOEFL 及 IETLTS 的考試成績排名。在那個排名當中，台灣是倒數的。使的大家開始懷疑我們外語教育即能力。台灣是非常注重英文能力的國家，為何成績會這麼差? 但是我要提出的疑問是，光從這個排名就可以斷定我們的英文能力嗎?

我認為台灣考TOEFL或其他語文測驗的目的跟其他國家不一樣。考TOEFL不外乎就是要出國留學，這也是大部分的國家考TOEFL的原因，但是台灣許多的工作也會希望看你的TOEFL成績。會不會因為考試的目的不同，所以造成準備的心態不一樣，導致考試出來的成績不一樣? 例如，我相信在日本考TOEFL的人都是要出國的人，而要出國的人通常對自己的英文程度是有信心的，也通常做了很透徹的準備。

另一個疑點就是，這個排名是看平均成績，但是標準差呢? 我相信台灣的標準差會比其他國家大很多，因為考試的目的種類較多。我也相信若拿台灣考試成績的前百分之十跟其他國家比，成績會很亮眼。

Forensic Economics

美國有一個很紅的電視劇叫CSI，每一集的故事就是有一群forensic scientists，利用科學的方法分析證據尋找壞人。近幾年來forensic science在美國越來越紅，主要原因就是因為這齣劇跟李昌鈺的關係吧。

然而，現在執法者也越來越養賴經濟學家了，而經濟學家也對crime也越來越有興趣。其實經濟學家很早就開始研究犯罪了，但是因為蘋果橘子經濟學(freakonomics)的興起，使得大中開始了解經濟思維在這方面也有貢獻之處，因此執法單位開始聽取經濟學家的建議了。

例如，最近有一篇文章 "利用證據" 試圖找尋 "非法武器交易" (就像軍火之王)。他們所使用的證據是 "股價"。當UN的武器交易法變嚴格時，他們發現比較有可能從事非法交易的武器公司的股價會相對上升， 而遵守法律的公司會相對下降。