Wandering EconMan

Egypt Trip

2009-07-28T16:16:00.002+08:00

喔! 對了! 我沒有去埃及。駐以色列的埃及大使館不給簽證，所以無法盜開羅等地區。但是我下星期想去Sinai試試看。

話說我打電話給在以色列的台灣辦事處，詢問看看，是不是他們跟以色列的代表打交道時得罪了別人，或是我們臺灣人得罪了他們，還是我們的政府? 埃及的人很會記仇的。有一個印度人說，40年前有一個印度情報人員被抓，埃及始終沒有原諒，所以印度人也會被拒。

然而，這邊的代表給了我一個很簡單的答案: 因為中國! 因為埃及為了展現對中國的忠誠度，所以拒發簽證給我這種旅客。只有跟旅行團有可能。

這完全不合理!

我的中國朋友也都拿不到簽證，哪有人這樣展現誠意的阿? 官方的答案 (善意的謊言) 也是需要輔合邏輯的，希望外交部可以在這一方面加強一些。

我認為是因為埃及跟這邊的其中一個旅行社有關係 (親戚關係吧!)，所以未了幫他們招攬生意，所以拒發簽證，然後失望的背包客只好到那一家旅行社 (就在大使館對面!!) 報名參加旅行團才能去埃及 (要花400美元參加2天的旅行團!?)。

我說不了! 我拒絕跟他們阿拉伯人玩這種第三世界的小遊戲。我跟埃及大使館的人說，我也不希罕去你們那國家。吃那種會讓你拉肚子的食物，走在只會被一群乞丐騷擾的街道，觀看滿是垃圾的尼羅河。我在電視上看到的金字塔肯定比我自己去看的還美。è 酸葡萄!!

以後埃及會邀請我去他們那邊的，我相信。

Dead Sea and Masada

2009-07-28T15:58:00.001+08:00

這是誰? 但說實話，敷完後，皮膚像嬰兒的一樣嫩。

2004年的時候死海的岸邊還到那藍色牌子那，但是現在死海的面積極速驟減。你可以看2000年的時候跟2004年比起來，感覺這5年間縮的比以往多。

其實到了那，你也不會管這一些東西，浮在上面還真舒服。很多人買報紙，為了拍在死海上面看報紙的照片。但是在那邊賣的報紙有150台幣。很坑!!

這是Masada，在一個禿起的平台上所建的城堡，之後被羅馬人攻陷。猶太人為了不被羅馬人俘虜，在上面集體自殺，雖然違反猶太教，但是寧死也不要淪為羅馬人的奴隸。說實話，猶太人跟基督徒的恩怨還比較深!

臨死時所看到的天空不知道是不是這麼藍?

往下看全是羅馬的兵

那方塊就是當時羅馬人所建的營區。他們建造了7個之多，全部環繞著Masada。

在這上面看的到死海

Western Wall and The Tunnels

2009-07-28T15:37:00.001+08:00

在地底下行走，這是古時侯的街道。

這不是一張很好的照片，但是底下這一快石頭有一輛公車大，570頓的石頭。是人類史上，沒有用機器，所搬運過最大的物件。

大家在禱告

我也應該跟上帝說說話。看牆裡的隙縫都是紙，這一些prayers都會被收集起來然後被埋起來。然後看我的頭上有一個白白的東西，那是紙的瓜皮帽。

Oh Tom!

2009-07-20T16:12:00.002+08:00

Thoughts on this later. It will be a lengthy post on this year's Open

明天去埃及

2009-07-16T05:55:00.002+08:00

我有將近2星期的時間不在電腦前。但是回來後，除了埃及的照片與感想，我一定要跟各位分享這一些東西:

1. 我搬到特拉維夫市中心後的生活與心得
2. 我的以色列同學是如何準備GRE (這真的很天才，足以證明猶太人為何這麼厲害!)
3. 死海與Masada照片
4. 巴勒斯坦的照片與發生在我身上的一些有趣但是也很緊張的故事。
5. 耶路薩冷老城的更多歷史背景與照片。
6. Sea of Galilee (這是我2個月前去的地方，都還沒跟各位分享!)
7. More pictures
8. 講更多關於我在summer school學到的東西，不一定是經濟的。

我猜講完這一些東西，我可能就回到台灣了。

Thoughts on the Summer School: The Lecturers

2009-07-04T02:28:00.002+08:00

這肯定是我參加過最棒的暑期課程! 整個課程安排，老師與學生及學術氣氛都讓我印象深刻。當然，當你邀請的講者有Eric Maskin, Jean Tirole, Bengt Holmstrom, Oliver Hart, Philippe Aghion 與 Mathias Dewatripont 的話，課程怎麼可能不精采。而教室裡又有 Kenneth Arrow 坐在台下問問題，而 Robert Aumann 就在走廊上晃盪，任何學生在這種環境下都會覺得很幸福。

Eric Masin 我幾乎每一年都見到他，從2007年開始，當他還沒拿諾貝爾獎時，到今年這一次的暑期課程。我報告我的海報時他也有特地跑來聽，也問了很多問題，其中給了一些寶貴的建議，也不忘記鼓勵我。大家說他是我們學界最 nice 的人，我這一次是真的親身深刻的體驗到了。當他在吃午餐時，有同學跑去跟他道謝，他馬上站了起來。

Jean Tirole 可能是這一次所有同學最期待的講者。我在台拉維夫的朋友只有來聽 Jean Tirole 講課，而許多同學也只找 Jean Tirole 聊天。這無可厚非，他畢竟是當代影響力最大，生產力最驚人，最有創意的經濟學家之一。他上課時也表現的很穩重很有自信，聽他講課很吸引人，但那也可能是因為他的題目太有趣了 (他現在在為一些行為經濟學家及實驗經濟學家所做的結果尋找合理的解釋。) 我下課時也跟他聊了一下，也跟他介紹了我的研究，他還沒聽完就已經知道我是怎麼設計的，也不斷提醒了我這樣做的缺點。

Oliver Hart 可能是這一群講者裡最有可能拿諾貝爾獎的，因為他開創了 incomplete contracts 的研究也解釋了為何公司要合併或分裂。(Tirole 也一定會拿，只是我不知道他是會因為什麼貢獻而拿。)
他老人家上課時很愛講冷笑話，講完後面無表情的繼續上課。有一次同學問問題，他跟大家講了一個故事，講完後才發現好像跟問題沒有關係。大家去死海玩的時後，他也跟來了，不忘帶他老婆一起來，是跟我們一起來的唯一的老師。在死海飄浮時，還差一點撞到我，於是在海上小聊了一下。是一個蠻喜歡消遣自己的人，這種個性我蠻欣賞的。

Philippe Aghion 是一位典型的法國人，講課時帶著濃濃的法國腔，上課時的語氣也很激情，看他上課心情會很好。他也是一位典型的書呆子。我第一次看到他時，他抱著他厚厚的手提包走來走去。上課時，沒人問問題，他也以會以為有人問問題。第一次上課時，上到最後他問 Eric Maskin 他還剩下幾分鐘，Maskin 跟他說還剩 15分鐘。他呆呆的看著 Maskin 說: 喔完了! 我以為我還有 45 分鐘。有一次他講他的研究時，講到實證結果 (他主要是做理論的)，Ken Arrow 問他說，你的 R-squared 呢? 他很緊張的尋找，發現他並沒有方在 power point 裡，一直跟大家道歉。我在廁所裡排隊，他跑進來，排在我後面。下一堂課是他要講，所以我跟他說我很慶幸他排在我後面。他開懷大笑，並拍我的肩膀說，這樣你一定不會遲到。非常平易近人，熱情的老師。

Bengt Holmstrom 也是一位很有趣的人。上課時很搞笑，沒事就消遣 Oliver Hart。Oliver Hart 有一次上課時，Holmstrom 在台下看自己的書，Hart 就問他說，你在看什麼東西阿? 你到底是不是學生阿? (其實，Hart 再講的東西是他跟 Holmstrom 的東西。) 他有一次上課時符號搞混，因此要回去更改符號，有一位台下的老師就建議他把福號改成 tau，他卻說: 不行，我等一下要用 tau。有老師建議改成 z，他也說不行，他等一下要用 z。最後他決定用大寫代表，不久後他看著他的筆記，他笑著說: 我的筆記也是用大寫寫的。你一定要再現場才會覺得好笑。

暑期課程也有找 Aumann 來講課。他講他最近作的研究，用了很多動物行為的實驗結果以及人類的異常 (在經濟學的眼中是異常) 行為做解釋。而不實的就冒出自慰，或是一些其他相關的字眼。看著一位將近80歲，帶著小瓜皮帽，留著滿臉白鬍子的諾貝爾獎得主講這一些字，可能令許多人印象深刻吧!

US Open: Reflections

2009-06-25T02:19:00.002+08:00

從上星期開始，雖然我的學期已經結束了，但是我仍然有暑期課程。我每一天早上6:30起床到耶路薩冷的西柏來大學上課，大都晚上8:00到家，所以都沒有時間經營這部落閣。

我先講一下我對美國公開賽的看法:

Lucas Glover 贏了，但是這一次的美國公開賽的故事卻不是他。
其中的故事是 Phil Mickelson。最後一天還有一度並列領先，但是最後的結果是他已經熟習的第二名。他現在是史上在美國公開賽拿下最多第二名卻沒有贏過的選手。
David Duval 回來了! 嗎? 他的表現很穩，感覺他的球感已經回來了。但是他以前也有很好的表現，但是過幾個星期就不見了。他的確是胖了很多!
Ricky Barnes 太可惜了。最後一天打76。雖然後九洞有回神，但是前九所犯的錯誤太嚴重了，無法彌補。我7年前預測這小子會是高爾夫球很重要的未來之星，但是等到現在他沒有什麼重要表現。我覺得他已經成長許多，拭目以待。
老虎怎麼了!? 感覺他的推杆一直是問題。可能1年沒碰杆子影響最大的是短杆吧?

US Open Highlights: Round 1 and Round 2

2009-06-20T13:14:00.002+08:00

Hello Ricky Barnes! 當他贏了US Amateur 之後，許多專家以為他會再PGA 很成功，但是這幾年卻一直沒有breakthrough.

若Mickelson可以贏，這可能會被拍成電影。

我覺得Mike Weir很有機會。他名人賽也是在溼冷的狀況下贏得的，而且他看起來蠻有信心的。但是我當然希望看到Mickeson終於贏得美國公開賽。

如何自我介紹?

2009-06-06T15:01:00.003+08:00

From Cheap Talk:

Most economists dread these moments when someone asks you what you do and you have to tell them you’re an economist and then prepare to deflect the inevitable questions and/or accusations “what’s going to happen with interest rates?” “when’s the economy going to turn around?” Usually I just mumble and wait for the person to get bored and go on with her reading. For some reason I was talkative today.

I told her I was a game theorist. “What’s that for?” I told her I was working on a theory of torture. She looked horrified. “How do you make a theory of torture?”

I told her that using game theory is a lot like screenwriting. Imagine you were a film-maker and you wanted to make a point about torture. You would invent characters and put them in the roles of torturer and torturee and you would describe the events. You would depict how the torturer would plan his torture and how he would the torturee would react and how this would lead the torturer to adjust his approach. If the film was going to be effective it would have believable characters and it would have to show the audience a plausible hypothetical situation and what happens when these characters act out their roles in that situation. In short, its a model.

當你是學生時就沒有這麼好辦了。因為大家問的是: "你念什麼系?" 而不是: "你作什麼研究?" 因為沒有賽局系，所以你只好乖乖的回答 "經濟系"。每一次我一回答經濟系，尤其是這一年半，就會有人眼睛發亮猛問我覺得經濟什麼時侯才會好轉? 或是政府應該怎麼應付? 或是消費卷是不是好的政策? 等等問題都會讓我發冷汗，雖然我可以回答一些問題，但是我的答案也大多是從報章雜誌所看到的，應付一下而已，應該不會比一般人了解的更多。

我會通常補一句說: "經濟學蠻廣的，我喜歡研究的是個體經濟學，尤其是賽局理論的應用。" 這時就會有人說: "賽局理論喔! 那你玩撲克牌一定很強!" 不然就是覺解釋一下後，就覺得這東西"太深奧"，就不繼續追問了。

對我而言，我也覺得我在做的工作像是再寫一齣劇。所以我完全同意 Jeff Ely 的看法。我可能以後會直接講說我是劇作家。這樣以後可能會有更話題。

Amadeus

2009-06-04T15:22:00.002+08:00

前幾天買到廉價的舞台劇的票。剛好演出的是 Amadeus。我小時候看過翻拍的電影，到現在記憶猶新。

這是在他們以色列最有名的劇場之一，Camari Theatre，演出。全戲以希伯萊文演出，但是有舞台上方有英文螢幕，所以我不至於完全看不懂。但是後來仔細思考過後，不看字幕，只看演員表情也會很清楚的了解故事劇情，可能還會更欣賞整齣劇。

有趣的一天

2009-06-04T15:07:00.002+08:00

星期二早上我坐在我的研究室，突然警報器響起，是那種我們以前國小空襲演習時用的警報器。

剛好我前一天晚上跟我室友聊伊郎的問題，他說: "那群傢伙有了核子武器鐵定攻打以色列，百分之百。"

我看著他笑說: "若真是這樣你怎麼看起來一點都不緊張?"

他說: "我們已經習慣了! 國小時常不用上學因為伊拉克的火箭在以色列空中。"

而我的研究室同伴也說以前覺得很好玩: "天天不用上學! 以色列有很多問題的，但是我們都已經認清這事實了!"

而當警報器在響時，我蠻緊張的。因為我知道我身處在一個有20幾個國家想攻打的國家。甚至有一些國家不惜自身安全，就是要把以色列給摧毀。但是我當時只看到一群博班同學嘻嘻哈哈的往防空洞移動。他們看到我就說: "這只是演習不用怕!"

我問說: "若不是演習呢?"

他們說: "那這也不是我們能控制的阿!"

約旦: Part 4

2009-05-30T14:35:00.005+08:00

前3次介紹的都只是我去的第一天的照片。今天放我第二天去的照片。第二天仍在Petra，但是我決定騎看看驢子，也打扮的像當地的阿拉伯人。

擺個Pose

我們的導遊Esa

與Beduin小孩喝茶。這就是他的家了。

晚上在Petra的夕陽

睡覺前吸個水煙。吸的臉都紅了。我只有吸一口!

The Schedule is Out!

2009-05-21T03:49:00.007+08:00

光看這份檔案就會讓人熱血沸騰!

VICTOR ROTHSCHILD MEMORIAL SYMPOSIA

THE INSTITUTE FOR ADVANCED STUDIES

THE HEBREW UNIVERSITY

20th Jerusalem Summer School in Economic Theory

THE ECONOMICS OF CONTRACTS

June 19 – 30, 2009

Director: Eric Maskin (IAS Princeton)

Codirector: Eyal Winter (The Hebrew University)

TENTATIVE PROGRAM

Friday, June 19

09:00-10:00 Registration

10:00-11:30 Eric Maskin (IAS Princeton)

Opening Talk - An Introduction to the Theory of Contracts

11:30-12:00 Coffee break

12:00-13:30 Philippe Aghion (Harvard)

Openness and Freedom in Academic Research: Theory and Evidence

13:30-14:30 Lunch

Saturday, June 20

Sunday, June 21

10:00-11:30 Philippe Aghion

The Governance and Performance of Universities

11:30-12:00 Coffee break

12:00-13:30 Mathias Dewatripont (University of Brussels)

Contract Theory and Banking Regulation I

13:30-14:30 Lunch

14:30-16:00 Philippe Aghion

Technology and the Internal Organization of Firms

Monday, June 22

10:00-11:30 Philippe Aghion

Innovation and Financial Organization and Regulation

11:30-12:00 Coffee break

12:00-13:30 Mathias Dewatripont

Contract Theory and Banking Regulation II

13:30-14:30 Lunch

14:30-16:00 Mathias Dewatripont

Contract Theory and Banking Regulation III

Tuesday, June 23

10:00-11:30 Omri Ben Shahar (University of Chicago)

Remedies for Breach of Contract

11:30-12:00 Coffee break

12:00-13:30 Jean Tirole (University of Toulouse)

Cognition, Motivation, and the Meaning of Contracts and Performance I

13:30-14:30 Lunch

Wednesday, June 24

10:00-11:30 Jean Tirole

Cognition, Motivation, and the Meaning of Contracts and Performance II

11:30-12:00 Coffee break

12:00-13:30 Oliver Hart (Harvard)

Introduction to the Theory of the Firm

13:30-14:30 Lunch

14:30-16:00 Jean Tirole

Cognition, Motivation, and the Meaning of Contracts and Performance III

Thursday, June 25

10:00-11:30 Eric Maskin

Contracting with Asymmetric Information I

11:30-12:00 Coffee break

12:00-13:30 Omri Ben Shahar

Filling Gaps in Incomplete Contracts

13:30-14:30 Lunch

14:30- 16:00 Oliver Hart

Property Rights Theory

Friday, June 26

10:00-11:30 Oliver Hart

Reference Points

11:30-12:00 Coffee break

12:00-13:30 Eric Maskin

Contracting with Asymmetric Information II

13:30-14:30 Lunch

Saturday, June 27

Tour to Masada

Sunday, June 28

10:00-11:30 Oliver Hart

Firm Scope

11:30-12:00 Coffee break

12:00-13:30 Bengt Holmstrom (MIT)

Liquidity and Bank Runs

13:30-14:30 Lunch

14:30-18:30 Tour in Jerusalem (including lunch at Ramat Rachel)

Monday, June 29

10:00-11:30 Bengt Holmstrom (MIT)

Public and Private Supply of Liquidity

11:30-12:00 Coffee break

12:00-13:30 Poster Session

13:30-14:30 Lunch

15:00-16:30 Poster Session

Tuesday, June 30

10:00-11:30 Bengt Holmstrom

Liquidity Provision and the Role of Debt

11:30-12:00 Coffee break

12:00-13:30 Omri Ben Shahar

The Law of Contract Renegotiation

13:30-14:30 Lunch

比較讓人擔心的是我也報名參加海報的介紹，所以我這星期不去埃及了，只好待在宿舍用功努力了。

我真該死!!

2009-05-19T01:07:00.003+08:00

我的媽阿!

今天可能是我來以色列以來最氣自己的一天。我竟然忘記去上Helpman的課了! 最近過的很糊塗，但是我怎也沒想到會忘記這麼重要的事，這麼棒的課竟然給忘記!!

現在只好自己看論文了....

克魯曼：台灣健保全球最好.....誇張?

2009-05-16T21:35:00.002+08:00

我剛剛再Yahoo新聞看到這一則新聞報導。克魯曼老早就讚揚我們的健保制度。這不是讓我驚訝的東西。而是民眾對於這一則新聞的反應。

在最底下，讀者可以點選這一則新聞給他的感覺。而88%的讀者覺得誇張。謂何會覺得誇張?

Competition and Growth

2009-05-16T20:18:00.002+08:00

經濟學原理告訴大家，亞當斯密斯的完全競爭市場有個看不見的手可以達到最有效的資源分配。但是市場競爭對於經濟成長又是什麼影響呢? 這問題就難了! 而且讓一些經濟學家頭痛了將近40年，直到近5年才有比較明確的答案。

這問題難的原因是因為市場競爭對於廠商創新的意願有兩種作用。一方面，競爭越激烈，廠商就可能會越想創新，脫穎而出。但是另依方面，競爭越激烈，廠商創新後的利潤會比沒有競爭時還來的低，所以競爭反而降低了利潤，也因此降低了創新的意願。所以哪一種效果比較大呢?

這問題在40幾年前的實證研究上就引起了大家的注意。當時的實證研究顯示，競爭與成長的關係不單純。更明確的說，關係不是線性的，也就表示說並非競爭越激烈，成長就越快，也並非經爭越激烈，成長就越慢。所以這背後的理論又是什麼呢?

理論的發展，相對而言，感覺上就比較緩慢。一開始的理論，採用所謂的熊彼得效應解釋競爭與成長的關係。熊彼得效應就是說，競爭越激烈，創新意願越低，因為創新後的利潤反正也不高，所以乾脆不投資算了。這理論模型還風行了許久，一直都沒有正視當時的實證結果。直到90年代時，這個議題反而變的格外重要。怎麼說呢?

當時美國正覺得微軟變的太大了，影響了整個市場的競爭，變的沒有競爭了。要不要使用反托拉斯法限制微軟的一些行為。比爾蓋茲卻認為說，微軟的成功正是因為在激烈的競爭下，不斷的創新所打造出來的奇蹟。若不讓一家努力創新的公司享受成果，以後創新的意願就會降低，經濟成長就會受到阻礙。就是在這背景下，競爭與成長這議題變的非常重要。法官們與全世界的民眾都在思考這問題，然而經濟學家自己也不確定，反託拉斯法到底合不合理?

理論不斷的反覆修正，而計量經濟也一直在進步提共更好的實證工具。最後2003年時，理論與實證結果終於吻合了! 而且結果也很直覺。答案跟廠商自身的技術有關。若廠商的技術很前端，跟最先進的廠商同步，那麼市場競爭越激烈，創新的意願越高。這叫脫離效果，因為廠商希望能夠脫胎換骨，成為市場第一，所以不斷的創新。反觀，若落後前端科技很多的話，市場競爭越激烈，創新意願越低。這叫氣餒效果，因為就算創新，技術提升了，也只能勉強追上其他廠商，到時還是要跟他們競爭，所以創新後的利潤仍然不高。

這對於政府政策有很大的影響，要不要設立保護智慧財產權的法規? 要不要有反託拉斯法? 這兩個法規是同時存在的。但是我們的法官或是政府知道要在什麼時候使用它才最適當嗎? 我強烈建議政策制定者看這本書: Competition and Growth: Reconciling Theory and Evidence. 才80幾頁，但是看完後會覺得學到很多，這也是經濟學近幾年的法展成果，所以很直得大家閱讀。

我是覺得政府官員一定要看，因後最後一章講解自由貿易所帶來的競爭對於成長的影響。這跟以後台灣未來20年的發展有很大的關係，當我們與對岸的貿易越來越平凡後，哪一些產業政府應該保護，哪一些產業政府應該放手讓他競爭。這種問題不能憑感覺或是遊說來決定，這時就需要經濟的邏輯尋找答案。

BTW，6月底在耶路撒冷，我就會碰到作者了。所以現在都在惡補這一些大師的一些作品。

約旦: Part 3

2009-05-16T19:39:00.006+08:00

之前談到爬800階梯。這階梯是原始地形所刻出來的，所以經過幾千年的風化後，石頭變的很滑，很不好走。我時常走一走就會滑跤。而且頂著大太陽上去的時候，每到一個轉角就會希望已經到達目的地了，但是每一次希望都會落空，直到你已經走到沒有任何期望的時候，你就會馬上看到一塊空第，依排人坐在椅子上觀看Monsatery。這時你才知道你到達了目的地。還有力氣的人可以繼續爬，上面有一塊地方叫 the end of the world。

才剛開始我就已經累了

想想看已經走了幾個階梯

很高! 靠邊走比較安全

是不是這個轉角就到了!?

終於到了!

Self explanatory..

下回再跟大家分享騎驢子爬山的照片。

約旦: Part 2

2009-05-15T17:40:00.003+08:00

在峽谷間走了將近20分中後，你會突然間看到印地安納瓊斯跟他父親在第3集時所看到的景色。這時你會驚覺峽谷已經走完了，你即將進入2000多年前所建造的古城。城內的建築大多是建在岩壁內。在城內可能至少要花2天的時間才可以全部看玩。

初極狹，纔通人；復行數十步，豁然開朗。

印第安那瓊斯在這找到聖杯

裡面很適合玩躲迷藏

這是他們的公共劇場

俯瞰以前的大街，也是以前最繁華的街道

下一篇在跟大家分享爬800接梯到他們的Monastery。

約旦: Part 1

2009-05-15T16:27:00.007+08:00

我將近一個月前去約旦的照片遲遲沒有時間放在部落格上跟大家分享，真不好意思!

我們主要是去 Petra，我們在那待了2天，之後去他們首都Amman一天。這是一趟非常值得的trip，光是去Petra就讓我回味無窮了。

我們半夜12:30從Tel Aviv出發，早上5點多到達 Eilat 過邊境。一踏上約旦國土就是一望無垠的沙漠。我們搭乘計程車直奔Petra。一路上只有沙漠跟偶爾的幾之駱駝陪伴著主人，不然就是一些Beduin，游牧民族在沙漠上維生。

Welcome to Jordan

在這邊只能相信上帝了

駱駝是很溫馴的動物，但是有的時候看你不順眼還是會咬你一口

我們到了Petra之後馬上找住的地方，我們住在一間非常便宜的Hostel，一個晚上不到台幣150。放下東西後就馬上跑去Petra 逛古蹟。在那逛了兩天!

背包客注意! 超便宜的Hostel

入口，之後的每一步都會讓你驚嘆

要在這峽谷間走將近20分鍾的路才會進到老城

這是峽谷最深最窄的部份

向上看的景象

因為太多東西了我要分批介紹，所以下一篇在介紹老城內的景觀。

關於蟑螂的問題

2009-05-10T15:23:00.003+08:00

昨天半夜我的室友跑到我的寢室打蟑螂。當時我已經入睡了，聽到我的室友大驚小怪的，叮叮咚咚的跑到我的屋子裡來，跟我說有蟑螂!

他舉起腳來往下踏了好幾下，終於踩死了蟑螂。他驚奇的跟我說很大一隻，我起來看了一下，發現小的跟什麼一樣的。我跟他說這一點都不大。我室友說有兩個指節這麼大ㄝ!

我的問題是這個:
我認為蟑螂在演化的過程中為了減低被人類打死的機率，必須將身軀變小。我室友感覺沒有什麼打蟑螂的經驗，所以說明了以色列蟑螂沒有臺灣多，所以蟑螂被打的機率很小，所以應該比較大才對阿!? 為何台灣的蟑螂被拖鞋追著跑還是這麼大呢? 我想到有幾個原因:

演化不是很efficient，有可能要等個30年後台灣蟑螂才會變小。可能以色列以前的蟑螂也很大，時常被追著打，所以現在變小了。
這可能是內生性問題。以色列蟑螂小，所以不常被發現，所以我室友大驚小怪。台灣蟑螂大，所以才常常被打。
台灣的蟑螂在進行collusion。演化需要成本的，台灣的蟑螂討論決定不要花成本變小了，乾脆大家都一樣大，這樣大家被打的機率都一樣小。那為什麼以色列蟑螂沒有學會玩這種合作的均衡呢?
可能我的假設是錯的。演化的方向並不像我想的這麼簡單。

我覺得 (4) 是最有可能的答案。

John Bates Clark Medal 2009

2009-04-25T20:00:00.001+08:00

The winner is Emmanuel Saez.

Rejection

2009-04-25T16:55:00.001+08:00

第一次被拒絕，但也是我第一次投稿。
看樣子這暑假去不成巴塞隆納了。

但是沒有關係，今天晚上我要去約旦。過幾天後才會回來。

Holocaust Memorial Day

2009-04-21T18:44:00.006+08:00

今天是Holocaust Memorial Day. 我上星期在耶路撒冷也去了Yad Vashem，他們紀念Holocaust的博物館。是一個很莊重的博物館。以下是一些照片

Yad Vashem

這一排橄欖樹是為了紀念拯救過猶太人的英雄

這一顆是Oskar Schindler 與他太太的樹

我也到了Mount Zion 找尋 Schindler 的墳墓，上面擺滿了石頭，以示敬意。

其實我們中國在二次大戰也就了許多猶太人，因為進入上海不需要簽證，所以中國成為猶太人第二大的避難所，僅次於美國。其中貢獻最大的是何鳳山，人稱中國的Schindler。

看到了他們如此用心的去紀念二次大戰所發生的悲劇以避免再一次的發生，讓我感嘆為何我們中國人都沒有辦法效法他們，也用心的建立一個博物館紀念在二次大戰被日本人屠殺的同胞。

我的論文

2009-04-14T22:50:00.002+08:00

很多人都問我，我的論文是什麼。我其實只是想要答一個很簡單的問題，這問題就是:

How long does it take an individual to move from an entry level job to the highest position that he attains in the firm? How does this vary across organizations? For example, in academics the highest-quality departments seem to promote individuals much more rapidly than the lower-quality departments. Is this a fact and, if so, why? What does it indicate about incentives and performance?

這是 Edward Lazear 在他的書 Personnel Economics 的第145頁的問題。

Masters: Final Day

2009-04-14T02:21:00.002+08:00

最後一天頭條:

Kenny Perry: 剩下兩洞領先兩杆，眼看這他把獎杯拱手讓人。我很希望有機會可以看到他贏一個大賽，但是歲月不饒人。
Angel Cabrera: 總是在大賽裡表現出實力。兩個大賽，未來鐵定入Hall of Fame? 過去8場大賽三個人包辦了7個: Harrington 3個，Tiger 2個，Cabrera 2個。
Tiger and Phil: 雖然沒有贏，但是追趕的很凶，差一點就追到領先群了。大家都很期待這兩個人會在大賽碰頭。這一次碰頭後雖然沒贏，但是留給了球迷很大的想像空間。
Sergio Garcia: 這一次倒數第8名。打完後怪球場不公平，說他不管了，反正他就是來打，打完就回家。他這種小孩子氣讓人當笑話看。
球場: 這一次的球場變的比往年更簡單一些，許多球員都不知道明年或未來球場會如何。我個人是很喜歡今年的感覺。

Masters: Day 3

2009-04-12T17:32:00.002+08:00

第三天頭條:

Kenny Perry: 昨天記者會上一名記者問Perry，你想像你明天穿上綠夾克的感覺會怎麼樣? Perry 說他不去想，因為以前想了都會輸。我打賭他今天做夢一定會夢到!
Angel Cabrera: 阿根廷大老粗。球打的遠，短杆又精準，而這星期推杆變強了! 他現在不抽菸了，所以他昨天記者會上說他不知道要如何減輕自己的壓力。這聽起來不妙!
Chad Campbell: 美國大老粗。打的很穩，但是突然在第16洞犯了天大的錯誤。Double Bogey。但是這可能對他來說是好事。我覺得他在後面追趕會比在前面領先打的好。
Jim Furyk: 這10年來PGA最穩的球員之一。但是近一年半，時好時壞，讓球迷很為他擔心。這星期他第一天打66，第二天打了一個74!! 真不知道明天是哪一個Jim Furyk出現。
Tiger and Phil: 球迷一直希望這兩位星期天在大賽會同組。他們的願望實現了! 但是這兩個大降落後7杆，可能明天要打一個64或63才有機會。以這兩個人目前的表現，我覺得不可能!

誰會贏? 我猜會是Kenny Perry。他這一年來贏了4場比賽，是所有球員裡最多的。他有經驗，而球技又像一個25歲的年輕小伙子。他打的high draw就是適合這種球場。應該是他的了。

Masters: Day 2

2009-04-11T15:19:00.002+08:00

第二天頭條:

薑是老的辣: 48歲的Kenny Perry打68杆與C. Campbell並列第一。Perry是這幾年來最穩的球員之一。
11個Birdie!: Anthony Kim 抓了11隻小鳥，破紀錄! 這是他第一次參賽。
老虎: 連續兩天，同樣的故事。
Padraig Harrington: 地15洞被罰一杆，因為風移動了他的球，而他的杆子已經觸地。若他星期天輸一杆.....
Gary Player: 最後一名，最後一次參賽。
Greg Norman: 在第13洞打了一個double，Missed Cut。這也可能是他最後一次了。

囚犯困境

2009-04-10T18:15:00.006+08:00

這在各個經濟部落格上出現:

一些觀察:

沒錯! 兩個都選steal 是Nash equilibrium，但是這遊戲有3個Nash equilibrium! 有兩個都steal，其中一個steal另一個split。所以他不是一般所認識的囚犯困境，因為選擇steal只是weakly dominant，而不是我們熟知的strictly dominant 的情況。
更有趣的是後面的訪問，那個女的說她之前被騙過，所以這邊有一點學習，跟演化賽局裡的預測很像。
這可以收其一下資料，看看在多少錢的情況下人們會比較傾向於選擇steal，什麼情況選擇split。我認為小金額的時候選擇split的情況會很多，因為畢竟steal也沒辦法偷多少錢。而金額在增高時，steal的比例會增加，但是金額非常高時，split的情況應該會變多，因為反正split也可以拿很多，我乾脆split顧及一下自己的名聲。
而好像女性朋友選擇steal的比例蠻高的，這可能跟輿論有關。畢竟女生搶男生好像比較不會受到社會輿論的抨擊。

Best Tiger Woods Commercials

2009-04-10T18:08:00.001+08:00

The List

我最喜歡的是這個:

Masters: Day 1

2009-04-10T17:28:00.002+08:00

第一天的頭條:

球場: 今年天氣好加上主辦單位把旗位放在比較容易攻擊的地方，球員都笑著離開球場。
老虎的鐵杆跟推杆: 鐵杆很準，推杆不怎麼樣。32推有一點多。
Larry Mize: 50歲打67杆，不賴。
Padraig Harrington and Greg Norman: Harrington 69，Norman 70。兩位仍有機會締造理史。
林文堂: 看轉播時還看到中華民國國旗在電視上閃過去。可惜打77杆，應該會被淘太。

台拉維夫100週年慶

2009-04-05T21:53:00.010+08:00

你說巧不巧，我來的時候剛好慶祝台拉維夫100週年慶。猶太人從1909年開始正式在台拉維夫落腳。一些歷史:

In 1906, a group of Jews, among them residents of Jaffa, banded together to build a new garden suburb on the outskirts of Jaffa. The goal of the Ahuzat Bayit (lit. "homestead") society was to build a "Hebrew urban centre in a healthy environment, planned according to the rules of aesthetics and modern hygiene". In 1908, the group purchased 5 hectares (12 acres) of dunes northeast of Jaffa which were divided into 60 plots. Meir Dizengoff, who later became Tel Aviv's first mayor, was a member of Ahuzat Bayit. His vision for Tel Aviv involved peaceful co-existence with the Arabs.

Another housing society, Nahalat Binyamin, began to build on April 11, 1909, after holding a lottery to divide up the land. Within a year, Herzl, Ahad Ha'am, Yehuda Halevi, Lilienblum, and Rothschild streets were built; a water system was installed; and 66 houses (including some on six subdivided plots) were completed. At the end of Herzl Street, a plot was allocated for a new building for the Herzliya Hebrew High School, founded in Jaffa in 1906. On May 21, 1910, the name Tel Aviv was adopted. Tel Aviv was planned as a European-style garden suburb of Jaffa, with wide streets and boulevards.

昨天晚上正式開始慶祝，有許多以色列的藝人上台唱歌，一開始還有國際知名的指揮家 Zubin Mehta 帶領的以色列交響樂團演奏古典音樂。最後，就是DJ放音樂大家在街上狂歡。我平常是不參加這種活動的，我從沒跨過年就是一個很好的例子，但是想說這一次不去會很可惜!

交響樂在這鐵架後面

人真的很多

街上都是人

嫌我照的不好的人可以看這裡的照片。

踰越節

2009-04-04T15:54:00.002+08:00

我這邊放兩星期的假，因為猶太人要慶祝逾越節 (Passover)。這兩星期是做研究跟遊玩的好時候，希望兩者不會有衝突!

Cheapest Stimulus Plan

2009-04-04T15:36:00.002+08:00

Proposed by Jeff Ely:

Of course there are many illegal markets that would generate stimulus were they to be legalized. Here are some of the big ones.
1. Drugs
2. Guns
3. Prostitution (except in Nevada)
4. Gay prostitution (even in Nevada)
5. Gambling
6. Trade with Cuba
7. Liberalized immigration

的確，若以上的交易合法化會刺激經濟，而且政府不需要花一毛錢，這是很吸引人的。但是也是因為這種想法，大眾才會覺得經濟學家的道德標準過低。所以為了我的形象，我是不支持這提案的。

波幅越大好還是越小好 - 答案

2009-03-30T04:21:00.003+08:00

答案是越大越好，所以你應該選擇活在乙世界。

因為這油田就像一個選擇權，沒人規定你一定要現在開採石油，你可以等到油價變高的時候在開採。這觀念叫做實質選擇權。基本上就是將選擇權定價理論班到一般的投資。目前石油公司都是以Black Scholes公式來決定油價飆到哪裡時才開始開採石油。所以目前有一堆油田，但是石油公司都在等待對的時機來開採。

因為沒有人回答這個問題，所以原本要送的獎品: 以色列女兵寫真集，就我自己收起來了。

Bang! Say Bye Bye!

實驗經濟學缺乏的

2009-03-30T04:09:00.003+08:00

我這一學期修一門行為經濟學，老師是 Avner Shaked。他一開始是做理論的後來開始作一些實驗挑戰傳統賽局理論所預測的行為。有一些實驗非常有趣，也的確會讓大家對於我們目前現有的理論產生巨大的懷疑。

行為經濟學的研究過程是這樣的。通常一開始會做實驗。這一些實驗的情境都很清楚也很簡單，理論所預測的結果也是很明確的，但是實驗結果通常跟理論預測會有一段差距。這時候行為經濟學家就會開始推出新的理論來解釋這一些實驗結果。這新的理論比原先的理論更能解釋這一筆數據。最後，因為實驗設計很妙，結果也很意外，而新的行為理論也有突破性，所以就可以發表在一流的期刊。故事結束，大家都很高興!

然而，經濟學家都忘記了去驗證這新的理論! 物理學，化學，其他科學都會有人做同樣的實驗來驗證新的理論的正確性，但是我們經濟學卻因為過於著重在發表論文上而不願意做這種登不上期刊的研究。所以不斷的有新的實驗，有新的理論，但是卻都沒有人驗證這一些新的理論。Sad..

A New Series! 各位高中生不要來清大系列

2009-03-26T22:15:00.002+08:00

台灣雖小但是資訊不對稱問題實在很嚴重。這一系列的文章是希望可以分享我在清大6年的一些觀察及經驗，並且告誡無知的高中生: 若你可以來清大，就表示你有許多選擇，請務必慎選!!

Letter from NTHU (各位高中生不要來清大 Part 1)

2009-03-26T21:31:00.004+08:00

我收到這一封信:

各位同學：

大家好，2月23日計財系葉昊定同學於體育館觸電粹死，讓人心痛與痛心。痛心的是學校為什麼沒有做好防護措施，讓一個充滿希望與熱誠的年輕生命，從世間消逝。『前事不忘，後事之師』，學校針對此事件組成一調查委員會，一方面釐清責任歸屬；一方面做出具體建議，將學校營造成一個更安全的環境。調查小組已開了兩次會議，責任歸屬上尚有待澄清之處，惟委員們認為校園安全的改善不能等！

有人認為任何悲劇的發生都是一連串的『巧合』，似乎無法避免。但事實並非如此，悲劇是環境中已經存在著某些『危險因子』，而悲劇的主角不幸的在最差的時間，同時碰上了這些因子。將環境中『危險因子』適當適時的排除，悲劇發生的機會是絕對可以適當降低的！悲劇發生後，大家會說許多『如果』，但都為時已晚。重要的是平常要有所做為，將『危險因子』移除。為了確保校園公共設施安全，學校總務處、學務處(針對學生宿舍)及體育室(針對體育設施)原先即已設置網頁或BBS通報版，學校成員發現需要修繕的情況時，均可經此管道通報，也許是宣導不夠，總務處與體育室的管道的效益有限。

為了讓這些通報管道發揮更大的效力，目前學校已在學校首頁建置「校園安全通報」系統(https://www.help.nthu.edu.tw/)。請各位同學充份利用，把握每一個機會，清除校園中的『危險因子』，避免下一個不幸的『巧合』。

針對觸電一事，調查委員會誠懇的呼籲同學們提供過去二年在學校任何地方(尤其是體育館的活動看台)觸電的情事，請有此經驗的同學以真實姓名(包括系級)告知你曾觸電的地點、大致的時間及其他相關資訊也請告知，並請即刻回覆（通報之電子郵件信箱為mailto:nrjiang@mx.nthu.edu.tw）。葉昊定同學的母親曾表示，不希望別的學生發生同樣的不幸，學校也將此視為承諾。你的熱心提供資訊將有助於完成一個傷痛母親的心願。謝謝你的協助。
祝

學安

體育館意外事件調查小組召集人
陳信雄

這是非常不幸的事，我聽到之後，我自己也下一跳。心想那也有可能發生在我身上，因為我以前都時常會跟朋友在那打籃球。其實清大在公共安全上面確實做的很差，目前學校挖路，鋪路，一堆卡車載滿泥土跑來跑去的，實在很危險。有時候走路都可以看到鋼鐵裸露，若一些人走路一不注意就會給撞上去。怪手車挖路，時常就看著同學在怪手下面鑽來鑽去，因為沒有別的路可以走。我在以色列都覺得比在清大安全。有時真的會覺得，難道我們的命這麼不值錢?

答案: 真的很不值錢。我想到時學校只需要賠賞幾百萬就可以打發這件事了，而我們校長花600多萬在改裝自己的宿舍。 (敢保證他宿舍一定不會漏電，以後去他家打球。)

我的建議很簡單，把清華大學告到倒。這樣我相信以後我們學校就會更小心了! 不用開什麼會，開這麼多會只是想要報帳。也不用討論什麼責任歸屬，那也只是花時間在那踢皮球。開會討論責任只有當這單位沒有層級之分的時候才需要。清花大學已經有一堆人做在辦公室吹超冷的冷氣，掛著很大的頭銜坐在皮椅裡，很明顯得我們學校已經有層基之分了，不需要開會，反正坐在最高級的皮椅裡的人負責就對了。也不需要請同學跟他們說學校有什麼問題，同學都有講過。

然而，我很怕這種事還會一再的發生，因為每有任何一次的教訓夠慘痛。當大家把五年五百億花的差不多的時候，把自己的住處整修好後，可能這一切都會被遺忘。為了以後學弟的安全，希望葉媽媽可以讓清大記住。

學生證

2009-03-24T16:47:00.001+08:00

Chinatown in Tel Aviv

2009-03-23T03:17:00.009+08:00

其實這邊要什麼有什麼:

有豆腐乳

有各種油類

還有台灣出產的麵

都在這家店裡

轉角有理髮店，感覺怪怪的

說實話，我在這裡已經入境隨俗了。我都自己做以色列傳統食物。在超商買一大罐Hummus，跟一堆口袋餅，跟青菜與雞肉。把東西通通塞到餅裡，就好了!

East Jerusalem and The Occupation

2009-03-19T04:12:00.006+08:00

我星期一到耶路撒冷。我沒有去舊城，我反而到了東區看巴勒斯坦人的住處。想要更了解他們的歷史可以看參考這個。

密密麻麻的破舊房子，沒有柏油路，只友塵土飛揚的鄉間小路。

耶路撒冷東區這40年間是在以色列的管轄範圍之內。然而東區資源分配不均 (西區只佔耶路撒冷的40%的面積但是有一百多間圖書館，東區只有3間) 以及等等不平等的現象驅使了許多以色列的人道團體出來呼籲政府重視這問題。其中的一個就是ICAHD。他們專注在阻止以色列拆除巴勒斯坦人的房子。

許多巴勒斯坦人沒有錢登記自己的房子，因此他們的住處是不合法的，依以色列的法律是要被拆除的。許多巴勒斯坦人在沒有預警之下收到通知，一星期 (有時更短的時間) 內搬走，因為他們的房子一星期後將被拆除。這一些人沒有別的地方可以去。

這一棟大樓有250個人住，三月五日接到通知，明天將被拆除。

住在那的小孩

以色列軍事策略

2009-03-19T03:47:00.003+08:00

雖然已經2個月前，但是今天才發現這一則新聞。最重要的一句話:

The Israeli theory of what it tried to do here is summed up in a Hebrew phrase heard across Israel and throughout the military in the past weeks: “baal habayit hishtageya,” or “the boss has lost it.” It evokes the image of a madman who cannot be controlled.

"This phrase means that if our civilians are attacked by you, we are not going to respond in proportion but will use all means we have to cause you such damage that you will think twice in the future," said Giora Eiland, a former national security adviser.

瘋子的行為是無法預測的更是無法控制的。以色列的策略就是理性的發飆。當你對我發射一顆飛彈，我的還擊是一發不可收拾的，像個瘋子一樣。想要更了解這一切的道理可以看謝林的 "The Strategy of Conflict" 或是看這一篇文章。

別說你不想來: Economics Summer School

2009-03-15T01:03:00.003+08:00

快報名吧! 叫政府補助一下(反正跟馬英九說這可以救台灣棒球的!)，我可以到機場接你們的。

Shukhacarmel

2009-03-15T00:18:00.007+08:00

想要在台拉維夫買到最便宜實在的東西就要到他們最有名的傳統市場，Shukhacarmel。

街景，非常熱鬧，有一些店面前簡直是人擠人

因為太多人在買了，你對他喊說你要什麼，他就會丟給你，你再給他錢

隔街有藝術家賣自己的作品

當場就有藝術家秀給大家看

仰頭一望都是破舊的老房子

波幅越大好還是越小好

2009-03-11T01:16:00.007+08:00

這一學期修了 Robert Pindyck 的課。

他問了一個問題:

你是石油公司的CEO (假設你是純粹位你的股東著想)，所以你必須到處去開採石油。你同一個時間有許多個地方可以開採石油，所以石油蘊藏地 (注意! 這是還沒有開採的地，你有選擇不開採或是開採，這已經是一個很大的提示了!) 的價值是視石油價格而定的 (因為有許多個蘊藏地，所以個別地點的風險(的突發狀況)你已經被你分散掉了，你只要管石油價個帶給你的風險就好!)。
有兩種世界:
甲世界 - 石油價格永遠都 $50。
乙世界 - 石油價格變化莫測，有一半的機會漲到 $100，有一半的機會跌到接近 $0。

請問你若是石油公司，你的蘊藏地在甲世界值錢還是乙世界?

答案一星期後公佈 (要回答，並且給原因! 每一次一堆人來都不回覆!)

若你不知道題目在問什麼，我們在討論的東西是圖裡的東西的價值。

題外話:

上課的時候老師問大家是不是都知道這東西是什麼。有同學回答說: "當然知道! 布魯斯威力在拯救世界前就在這工作!"

Old Jaffa - Part 1

2009-03-11T00:28:00.008+08:00

Jaffa (Yafo) 是世界上最老的海港之一，有四千年之久。位於台拉維夫的南邊，走路走半個小時就可以到達。因為它的歷史，所以在這逛街跟在市區內逛街的感覺很不一樣。在這逛更有中東的感覺，也更輕鬆。在這裡走路不會擔心自己是觀光客，猛拍照看起來很蠢，因為連以色列人也都到這裡來觀光，他們也拿著相機拍照。

有一些小巷感覺像是在電影內才看的到的，感覺非常新鮮!

入口處: 兩旁是跳蚤市場

許願橋: 看圖應該蠻容易懂得

很喜歡這種感覺!

我相機後來沒電了，所以有更多景象沒拍到，但是反正座個公車就到了，我還會再回去的。所以這只是 Part 1。

Happy Purim

2009-03-11T00:17:00.003+08:00

今天是 Purim。又是一個猶太人的節日! (我似乎來對時候了，這個季節特別多節目!)

這幾天都可以看到年輕人穿 costume 到處亂跑，參加 party。像我室友 (最左邊那一位女士):

他們都是醫學系的。

以色列的菁英!

清大梅竹賽終於贏了

2009-03-09T04:22:00.000+08:00

我一離開清大，清大就贏了?

台拉維夫經濟系

2009-03-09T04:04:00.003+08:00

這是以色列最棒的經濟系所以理所當然他就應該獨自擁有一個系館。

今天我跟一位碩班的同學聊天，他問我台灣的經濟系怎麼樣，我跟他說這邊的學生反應好快而且程度很好。他直接回我說: "那當然! 我們是猶太人!"

Diaspora Museum

2009-03-09T03:10:00.005+08:00

星期五，在Shabbath 開始之前，(上帝花了6天創造了世界，因此猶太人在星期五太陽下山之後到星期六晚上，都不能做任何事: 不能用火，不能創造東西 (包含寫作業等等)。這叫做Shabbath 或 Shabbat。因此這邊都是星期五與星期六放假，然後星期天到星期四工作。) 我跟鍾老師到我們台拉維夫大學校內的猶太人歷史博物館。

這應該是我看過最棒的民族博物館 (我覺得台灣可以參考看一看，客家文物館，或是原住民博物館可以做的更好)。以下是我照的一些照片。

行割禮用的器具

中國的猶太人都在開封? 所以包青天有沒有可能是猶太人?

博物館的出口

有幾個中國人?

2009-03-05T03:55:00.004+08:00

我跟一位香港的老師聊天，他也大約同一個時間來到台拉維夫。

我們聊到交通工具，他說他來到這覺得很難等公車，所以昨天就在台拉維夫大學做計程車回到他下榻的公寓。

我當天從學校走路回到我的宿舍時，一位中年男子跟我打招呼，我很訝異，因為我不認識他。
他跟我說: "你昨天做我的計程車!"

這只有一個解釋，就是這邊的老中真的很少。

Worst Weather in 6 Years

2009-03-05T03:42:00.002+08:00

我已經來到以色列一個星期了。原本打算好好利用這一星期來探索這陌生的國家。但是好死不死，我一到這邊就遇到以色列6年來最差的天氣，天天刮風下雨。我來之前的前幾天都還頂著大太陽，但是我一來之後每天起床都被雷雨聲叫醒。所以有一些人想要看照片的，很對不起，真的沒有什麼好照的。但是我有照一張地中海在暴風雨中的樣子，希望可以達到望梅止渴的效果。

ps. 今天開始以色列恢復正常，應該可以多出去走一走了。

Herbert Simon

2009-01-31T20:21:00.002+08:00

剛剛發現，開創有限理性的經濟學家: Herbert Simon，也有得過Turing Award。他應該是為一拿過Nobel Prize 跟 Turing Award 的人吧。

在Wikipedia 上有他在第一堂課都會講的一句話:

This is the last lecture I am giving you. From next class on, I will only respond to your questions. This course has plenty of readings. If you don't have questions, it is either because you have not done your reading, or you are too stupid to be in this course.

Wise Words from Warren Buffett

2009-01-26T21:04:00.002+08:00

From an Interview:

SG: But there is debate about whether there should be fiscal stimulus, whether tax cuts work or not. There is all of this academic debate among economists. What do you think? Is that the right way to go with stimulus and tax cuts?

WB: The answer is nobody knows. The economists don’t know. All you know is you throw everything at it and whether it’s more effective if you’re fighting a fire to be concentrating the water flow on this part or that part. You’re going to use every weapon you have in fighting it. And people, they do not know exactly what the effects are. Economists like to talk about it, but in the end they’ve been very, very wrong and most of them in recent years on this. We don’t know the perfect answers on it. What we do know is to stand by and do nothing is a terrible mistake or to follow Hoover-like policies would be a mistake and we don’t know how effective in the short run we don’t know how effective this will be and how quickly things will right themselves. We do know over time the American machine works wonderfully and it will work wonderfully again.

I think that is very very close to the truth.

一般人眼中的經濟學家

2009-01-26T20:45:00.002+08:00

上星期奧斯卡提名名單出爐，其中 Richard Jenkins 飾演一名經濟學家被提名最佳男主角。經濟學家!!?? 天阿! 經濟學家有什麼好演的!? 我沒看過電影，但是影評是這樣描述男主角的:

When we first meet Walter Vale (Richard Jenkins), he is in a state of emotional inertia that clinicians might identify as depression. He does not seem acutely unhappy, but then again, he doesn’t seem to feel much at all, locking whatever inner life he might have behind an aloof, unfailingly polite demeanor and keeping a glass of red wine handy in case further anesthesia should prove necessary.

A professor of economics at Connecticut College and a widower, Walter plods through an existence that looks comfortable and easy enough, but also profoundly tedious. He recycles old syllabuses and lecture notes for his classes, and suffers through piano lessons in a half-hearted effort to sustain some kind of connection to his wife, who was a classical concert pianist.

恐怕以後有故事想要描述一位鐵石心腸或是與世隔絕的人都會想用經濟學家來做文章了。

我今年再也不寫了

2008-12-31T23:29:00.001+08:00

我停筆了!!

The Future of Economics

2008-12-31T13:56:00.002+08:00

Something that I 'partially' agree with. From MR:

In my possibly overdogmatic view, economics is most useful when its models are relatively simple and intuitive. We've run out of new models which are simple and intuitive. So the theory game is over. The standard, old data sets have been data mined to death. We're now on to the "can you build/create your own data set?" game. That game can and will last for a long time; in some ways it will favor go-getter extroverts just as the theory game favored introverts.

I think theory still has a bright future. The fact that our current models are flawed means that we can still find better ones. Whether or not they are still simple and intuitive is another thing, but that depends on the modeler's skill. Good theorists can still provide us with simple and plausible economic models.

Sometimes for new discoveries to occur, we need to throw away the old framework that we have been working with for so long. When marginal analysis was introduced to economics, it catapulted our subject to the forefront of social sciences. When information asymmetry was introduced, every subject in economics was fundamentally changed. We are at the edge of another breakthrough, I think.

Am I too optimistic?

A Good Question

2008-12-31T13:53:00.000+08:00

Another Application of Game Theory

2008-12-23T23:10:00.002+08:00

From Freakonomics blog. Game theory and test taking, from Dixit and Nalebuff's new book: The Art of Strategy.

Consider the following question for the GMAT (the test given to MBA applicants). Unfortunately, issues of copyright clearance have prevented us from reproducing the question, but that shouldn’t stop us.

Which of the following is the correct answer?
a) 4π sq. inches
b) 8π sq. inches
c) 16 sq. inches
d) 16π sq. inches
e) 32π sq. inches

O.K., we recognize that you’re at a bit of a disadvantage not having the question. Still, we think that by putting on your game-theory hat you can still figure it out.

Before reading their analysis, take a shot at trying to reason your way to the correct
answer.

Here’s what they said:
The odd answer in the series is c. Since it is so different from the other answers, it is probably not right. The fact that the units are in square inches suggests an answer that has a perfect square in it, such as 4π or 16π.

This is a fine start and demonstrates good test-taking skills, but we haven’t really started to use game theory. Think of the game being played by the person writing the question. What is that person’s objective?
He or she wants people who understand the problem to get the answer right and those who don’t to get it wrong. Thus wrong answers have to be chosen carefully so as to be appealing to folks who don’t quite know the answer. For example, in response to the question: “How many feet are in a mile?” an answer of “Giraffe,” or even 16π, is unlikely to attract any takers.
Turning this around, imagine that 16 square inches really is the right answer. What kind of question might have 16 square inches as the answer but would lead someone to think 32π is right? Not many. People don’t often go around adding π to answers
for the fun of it. “Did you see my new car — it gets 10π miles to the gallon.” We think not. Hence we can truly rule out 16 as being the correct solution.

Let’s now turn to the two perfect squares, 4π and 16π. Assume for a moment that 16π square inches is the correct solution. The problem might have been: “What is the area of a circle with a radius of 4?” The correct formula for the area of a circle is πr^2. However, the person who didn’t quite remember the formula might have mixed it up with the formula for the circumference of a circle, 2πr. (Yes, we know that the circumference is in inches, not square inches, but the person making this mistake would be unlikely to recognize this issue.)

Note that if r = 4, then 2πr is 8π, and that would lead the person to the wrong answer of b. The person could also mix and match and use the formula 2πr^2, and hence believe that 32π or e was the right answer. The person could leave off the π and come up with 16 or c, or the person could forget to square the radius and simply use πr as the area, leading to 4π or a. In summary, if 16π is the correct answer, then we can tell a plausible story about how each of the other answers might be chosen. They are all good wrong answers for the test maker.

What if 4π is the correct solution (so that r = 2)? Think now about the most common mistake: mixing up circumference with area. If the student used the wrong formula, 2πr, he or she would still get 4π, albeit with incorrect units. There is nothing worse, from a test maker’s perspective, than allowing the person to get the right answer for the wrong reason. Hence 4π would be a terrible right answer, as it would allow too many people who didn’t know what they were doing to get full credit.

At this point, we are done. We are confident that the right answer is 16π. And we are right. By thinking about the objective of the person writing the test, we can suss out the right answer, often without even seeing the question.

Now, we don’t recommend that you go about taking the GMAT and other tests without bothering to even look at the questions. We appreciate that if you are smart enough to go through this logic, you most likely know the formula for the area of a circle. But you never know. There will be cases where you don’t know the meaning of one of the answers or the material for the question wasn’t covered in your course. In those cases, thinking about the testing game may lead you to the right answer.

The joke is on us

2008-12-10T10:38:00.002+08:00

From ptt:

1. 看不見的手
一群功夫學生要畢業了, 老師諄告他們: 出去以後, 千萬不能和經濟學家過招,因為他們都有一隻看不見的手.

2. 市場萬能
學生: 既然市場是萬能的, 那麼我們還要經濟學家有什麼用?
老師: 因為經濟學家能給我們帶來快樂, 而這是市場做不到的.

3. 完全競爭
第一天, 上帝創造了太陽, 接著魔鬼創造了灼傷;
第二天, 上帝創造了性, 隨後魔鬼創造了婚姻;
第三天, 上帝創造了一位經濟學家, 而魔鬼陷入了沉思...思前想後了好一陣子, 魔鬼也創造了一位經濟學家.

4. 預測衰退
經濟學家預測出了過去5次衰退中的9次.

5. 經濟學家定律
經濟學家第一定律: 對任何一位經濟學家而言, 一定存在著一位實力旗鼓相當的同時觀點又針鋒相對的經濟學家.
經濟學家第二定律: 他們都是錯的.

6. 論文發表
問: 你應該到哪裡發表論文?
答: 如果你能理解並能證明, 那麼就寄給數學雜誌;
如果你能理解但無法證明, 那麼就寄給物理學雜誌;
如果你不能理解但能證明, 那麼就寄給經濟學雜誌;
如果你既不能理解也無法證明, 那麼就寄給心理學雜誌.

7. 總統的困惑
美國總統和俄羅斯總理在高峰會談的間歇閒聊. 俄羅斯總統對美國總統說: 你知道嗎, 我遇到了一個麻煩. 我有一百個衛兵,但其中一個是叛徒而我卻無法確認是誰.
美國總統則說: 這算不了什麼. 令我苦惱的是我有一百個經濟學家,而他們當中只有一人講的是事實, 可每一次都不是同一個人.

8. 智慧的顯現
一位經濟學家去華盛頓的自然歷史博物館參觀. 當站在恐龍化石面前時, 他對身邊的遊客說: 這只恐龍的歲數足足有20億年又10個月.遊客驚訝且恭敬地問道: 您從哪裡得到如此準確的信息? 經濟學家不無自豪地回答說: 10個月前我來此參觀過. 那時講解員告訴我這只恐龍已經20億歲了.

9. 經濟與政府行為
如果經濟在運轉, 那就徵稅;
如果經濟不斷地在運轉, 那就監督;
如果經濟停止運轉, 那就補貼.

10. 學派之分
問: 要多少個經濟學家才能把一個壞燈泡換掉? 答: 八個. 一個把燈泡裝上, 剩下的負責保持其他條件不變.
問: 要多少個芝加哥學派的經濟學家才能把一個壞燈泡換掉? 答: 一個也不用. 要是燈泡壞了, 市場機制自然會把它更換.
問: 要多少個新興古典學派的經濟學家才能把一個壞燈泡換掉? 答: 那就要看當時的工資如何.
問: 要多少個凱恩斯學派的經濟學家才能把一個壞燈泡換掉?
答: 愈多愈好. 因為這樣便可增加就業, 刺激消費, 使得總合需求曲線向右移.

11. 經濟與天氣
問: 上帝為何創造經濟學家?
答: 因為有經濟學家的話, 天氣預報便顯得準確得多了!

12. 理論與實證
假如有一千名經濟學家去處理換燈泡的問題, 當中會有十個理論經濟學家, 各人對換燈泡的方法有不同的主張.餘下的990個實證經濟學家就努力地去檢驗那一個的理論正確. 最後, 所有人仍是在黑暗之中.

13. 諾貝爾經濟學獎
唯有經濟學這一門學科, 會出現兩位學者互唱反調, 而他們卻分享著同一個諾貝爾獎.

14. 誠實與說謊
甲: 聽說經濟學家總在說謊. 你能否告訴我, 如何判定他在說謊?
乙: 經濟學家大都比較誠實, 很少掩飾. 你只要注意他的嘴就行了, 嘴一動就在說謊了.

15. 經濟學家的語言
美國聯邦儲備委員會主席格林斯潘的名言: 如果你覺得聽懂了我說的話, 那你一定是誤解了我的意思.

16. 絕對真理
一位經濟學家宣稱: 慶賀生日是一項有益身心健康的活動.統計數據表明, 一個人一生中歡度的生日越多, 他的壽命就越長.

17. 做愛什麼是經濟學家? 知道100做愛方法, 卻從未與異性交往的人.

18. 病毒
如果社會是電腦, 經濟學家就是病毒. 可大致分類如下:
利益集團經濟學家病毒: 其作用是把硬碟分割許多小單位, 每個單位均無任何實際用途,卻都聲稱自己是本機器上最重要的部件.
計量經濟學家病毒: 染上此病毒後, 60%的機器將在14%的時間裡丟失38% (正負3個百分點) 的數據.
政治經濟學家病毒: 佔用記憶體但不幹活, 只有到下次選舉才能清除.
政府經濟學家病毒: 你的系統無法工作, 但所有診斷程序都報告說一切正常.
社會主義經濟學家病毒: 造成當機, 毀掉硬碟, 並堅決否認此事發生過.
主流經濟學家病毒: 聲稱受到電腦上其他文件威脅, 並以「自衛」為借口刪除他們.
中央銀行經濟學家病毒: 確保它自己大於其他所有文件.
跨國公司經濟學家病毒: 刪除所有貨幣文件, 微笑著發出經濟即將變好的信息.
供給學派經濟學家病毒: 讓你的電腦沉睡4年, 醒過來卻發現債務增加了三千個億.
環境經濟學家病毒: 阻止你刪除任何文件.

19. 明天/昨天/今天
經濟學家到明天才會知道為什麼昨天預言的事情在今天沒有發生.

20. 錯誤
經濟學家就是這樣一種人, 他並不知道他所談論的. 但是, 他讓你覺得這是你的錯誤.

21. 社會主義/共產主義/資本主義
在社會主義制度下, 如果你有兩隻母牛, 你送一隻給鄰居, 以體現友好.
在共產主義制度下, 如果你有兩隻母牛, 你把它們送給國家, 而國家供應你牛奶.
在資本主義制度下, 如果你有兩隻母牛, 你賣掉一隻母牛, 以所得收入再購進一隻公牛.

I personally like 3, 5, 7, 14, and 20

Who is better? Jordan vs. Kobe

2008-12-10T10:29:00.002+08:00

This confirms what I have thought all along:

As you can see, out of necessity Jordan was taking on a large offensive responsibility early in his career; as his teammates got better, he slowly eased back on the workload, and his efficiency improved as a result. Kobe's story is the opposite: with great teammates early, he didn't have to do as much, but when Shaq left before the '05 season, Kobe was actually forced to take a larger role in the offense than even Jordan ever had to.

It's more interesting, though, to look at the efficiency levels the players maintained vs. their % of possessions used. The mark of a truly great offensive player is to maintain a high level of efficiency while taking on a large share of the team's offensive responsibility, and even though Kobe's numbers are impressive, Jordan is consistently more efficient than Bryant no matter if he's using more possessions or not. Also, note the translated defensive ratings: aside from their age-21 seasons, MJ is better (sometimes vastly so) at every turn.

In other words -- and this should be obvious -- when we watch Kobe play, we're seeing a far lesser version of Michael Jordan in action. Similar in style and mannerism, maybe, but when we translate the statistics for era, it becomes very clear that Jordan was actually the one "playing chess" while Bryant "plays checkers."

我笑了

2008-12-10T10:24:00.001+08:00

星期一發考卷，我發現我的成績都是2倍的成長。

只有在台灣

2008-11-30T22:21:00.002+08:00

前幾天，我在我的同學的MSN暱稱上看到了這麼一句話:

亞洲國家對法律的見解分析。

新加坡:一切禁止,除非法律允許

香港:一切允許,除非法律禁止

中國:一切禁止,包括法律允許

台灣:一切允許,包括法律禁止

而最近幾星期，我們越來越了解陳水扁這8年都在忙什麼了。一位國家領導人竟然也做出如此可恥的事，我們也不僅要問，為何在台灣會發生這種事?

我上星期在藍鷹打北區大專杯，我們清華大學拿下了冠軍，但是又是經過了一番波折。若大家記得的話，我們在2006年的大專杯也是遇到一些問題。然而這一次有一位明新科技大學的選手，沒有誠實的稟報成績，隔天被我們檢舉，因此喪失資格。當時，明新科技大學是團體組領先的。

對我來說，打比賽要照規矩來，你今天犯規了就是要接受懲罰。然而，在台灣，你必須顧及到比賽的和氣與主辦單位的面子。對我來說，是否要檢舉一位作弊的人是完全不需要去思考的問題，然而在台灣這種情重於法的詭異風氣下是要慎重考慮的。我們這一次做了對的事情，但是又得罪了一些人。從這一件事情可以看得出來，為什麼我們社會的精英也會為知法犯法的人辯護。

只有在台灣:
1. 一位打了別校的選手的教練還可以繼續在那學校任職，並且繼續擔任該校的高爾夫球教練。並且時常提醒大家，他並沒有"圍毆"，報紙寫錯了。這種人就是我所說的3D - dishonorable, dishonest and despicable。

2. 還會有教練極力擁護打人的教練，並且無時無刻的想辦法排擠清大高爾夫球隊，一抓到機會就使清大高爾夫球對難堪。當主辦比賽時，故意忘記將清大的選手列入成績表上。並且故意安排某校的教練頒獎給我們。這種人就是我認為最糟糕的人之一。就是因為陳水扁身邊有這種人，他才會理直氣壯的犯法。

3. 犯規的選手的教練還有臉露面頒獎。並且握著我的手，笑笑的說: "我們明年會再來!" 很好! 但是，有羞恥心的教練早就躲起來檢討了，怎麼會教出這麼糟糕的學生，丟臉死了! 這種人就是厚臉皮的人，就是入獄的前一刻還會高舉雙手吶喊: "你關的住我的身體，但是你關不住我的心!"

若此風氣不退，台灣是不會進步的，希望可以早日改進。

上星期五

2008-11-30T22:18:00.002+08:00

我們拿下北區大專北乙組團體賽冠軍

贏台大一杆，好險~!

A Major Problem: Sperm Shortage

2008-11-19T10:26:00.002+08:00

From Daniel Hamermesh at Freakonomics:

There’s a shortage of sperm in Britain! Apparently, Britain needs donations for about 4,000 women per year; to reach that number, about 500 sperm donors per year are required, while only 300 are currently registered. Things were fine until 2005, when a law was enacted allowing children of sperm donors the right to discover the identity of their father at age 18; simultaneously, the number of women who could use the same donor’s sperm was limited further.

How about outsourcing to other countries? Doesn't international trade somehow solves the problem?

What Obama should Learn from History

2008-11-11T14:05:00.000+08:00

Obama's Victory Speech

2008-11-10T19:02:00.000+08:00

In other words, the guy has class!

Homo Economicus vs. Homo Sapiens

2008-11-04T13:21:00.003+08:00

Behavioral economist Dan Ariely explains that conflicts between standard economic theory with our true behavior in PC vs. Mac style:

The imperfections of human beings:

Gifts:

The heartless and unbiased homo economicus:

The farsighted homo economicus:

The super-intelligent homo economicus:

The fomulaic homo economicus:

The homo economicus who never regrets:

Its Time

2008-11-04T13:09:00.002+08:00

Some of the best videos from Obama's Youtube Account:

The 30 minute infomercial:

The Real Debate

2008-10-30T00:34:00.002+08:00

The race for the white house is drawing to a close, and though there have been different issues being thrown around, all will agree that the most important topic for the next US president is the economy. Hence, even though your attention might be drawn to other more interesting but irrelevant issues, the real debate should be on the economy.

Amazing Science: Scotch Tape and X-rays

2008-10-30T00:31:00.001+08:00

What is the relation between the two? Answer: Scotch tape can create X-rays!

In the current issue of the journal Nature, Dr. Putterman and his colleagues report that surprisingly fierce flows of electrons were unleashed as the tape was unpeeled and its gooey adhesive snapped free of the surface. The electrical currents, in turn, generated strong, short bursts of X-rays — each burst, about a billionth of a second long, contained about 300,000 X-ray photons.

Who is Voting for Obama?

2008-10-22T10:25:00.001+08:00

Some answers may surpise you:

So a canvasser goes to a woman's door in Washington, Pennsylvania. Knocks. Woman answers. Knocker asks who she's planning to vote for. She isn't sure, has to ask her husband who she's voting for. Husband is off in another room watching some game. Canvasser hears him yell back, "We're votin' for the n***er!"

Woman turns back to canvasser, and says brightly and matter of factly: "We're voting for the n***er."

That Looks Awesome!

2008-10-21T22:51:00.002+08:00

Topology is fun! The videos below demonstrate this fact

Turning the Sphere Inside Out:

The Klein Bottle:

You had a Bad Day

2008-10-21T14:02:00.005+08:00

Brokers with Hands on their Faces

And don't forget about George!

Intrade is Being Manipulated

2008-10-18T21:11:00.003+08:00

Currently, the prices trading at Intrade:

Obama 83.4% of winning the election

McCain 16.1% of winning the election

However, not too long ago, Obama didn't have such a comfortable lead at Intrade. In fact, Intrade predicted a very close election, unlike other prediction markets which favored Obama. This caused some speculation that the traders at Intrade were pro-Republican. Now it is clear that McCain's winning probabilities were boosted by one particular trader:

An internal investigation by the popular online market Intrade has revealed that an investor’s purchases prompted “unusual” price swings that boosted the prediction that Sen. John McCain will become president.

Over the past several weeks, the investor has pushed hundreds of thousands of dollars into one of Intrade’s predictive markets for the presidential election, the company said.

“The trading that caused the unusual price movements and discrepancies was
principally due to a single ‘institutional’ member on Intrade,” said the company’s chief executive, John Delaney, in a statement released Thursday. “We have been in contact with the firm on a number of occasions. I have spoken to those involved personally.”

As you might guess, as much as this trader loves McCain, other more rational traders saw an opportunity to make money by selling McCain, and buying Obama. It didn't take long for Intrade to display the "true" probability of Obama winning.

It looks like its going to be a landslide!

The picture below shows the predicted distribution of electoral college.

5000 visitors!!!

2008-10-16T00:02:00.001+08:00

Small milestone!! I am ecstatic!

James Heckman on Obama

2008-10-15T23:59:00.002+08:00

Link

I do not think it's class warfare [Obama's economic policies], I think it's empirical economics. The real issue is the empirical content of the supply side economics dogma. It's pretty threadbare. The "real business cycle" theory is simply inconsistent with empirical evidence. That does not prevent it from being taught as gospel to students (it's really gospel not empirical evidence). I would first and foremost talk to Ray Fair (Yale) and Mark Watson (Princeton) about the evidence for the supply side model. What is ironic is that those who preach supply side practice a crude version of Keynesian economics that ignores all of those incentive effects claimed to be so important by the supply side theorists. The real question apart from the current turmoil is the longer run. Denying the value of investment in knowledge;in infrastructure;in basic science and education at all levels has been and will continue to be harmful to our long run health. In my mind Obama's eyes are fixed more on things that will improve the US economy in the next century. The basic data on the current crisis is still being revealed, but it's clear that the absence of serious regulatory oversight contributed mightily to the current problems. It's not class warfare; its about a future-oriented society.

What am I reading: Poincare's Prize

2008-10-15T22:38:00.005+08:00

This semester, I'm taking a course on topology, just for fun. Hence, I've grown more and more interested in stories about mathematicians who work in the field of topology, and no tale is grander than the race to prove the Poincare Conjecture!

Math enthusiasts will know that it is no longer a conjecture, but a theorem now. It was finally proven for n=3 by Grigori Perelman, an odd Russian genius who chose seclusion and anonymity over fame and glory. The book "Poincare's Prize" is full of stories about mathematicians who succeeded in proving the conjecture for certain dimensions (Smale proved n>4, and Freedman proved n=4), and others who spent the better part of their lives searching for one.

As if the writing wasn't enough, the lives of these mathematicians keep the reader engaged. The story of some of these mathematicians will bound to make the reader smile (people like Stephen Smale), some will evoke unlimited sympathy (all those who failed to find a proof), some will leave the reader angry (like Yau Shing Tung), and finally there is one person who will force the reader to imagine the unconstrained capabilities of the human mind, and that person is Grigori Perelman.

Perelman is the shining star of the book, his ultimate triumph and his withdrawal from mathematics and the media's attention not only makes for a potential Hollywood movie, but also forces the reader to think about the meaning of accolades and prizes, more importantly to ponder the underlying drive to find truth.

Below are some pictures of Perelman, taken by a person who spotted him on the subway in Moscow.

Paul Krugman Wins Nobel Prize

2008-10-13T19:47:00.002+08:00

As titled

I do not understand alot about internation economics beyond the concept of comparative advantage. However, everyone thinks that the award is well deserved.

However, I am surprised that he won the prize alone, despite the fact that there were serveral other economists who were instrumental in the development of the modern trade theory. People like Dixit, Helpman, and others. Bhagwati is very deserving too!

More Nobel Predictions

2008-10-10T19:07:00.002+08:00

Thomson Reuter's Predictions

Again, a very very strong list! Armen Alchian is 94 years old, I think. He definitely deserves it!

In light of the financial crisis, a large portion of economists think that Richard Thaler and Robert Shiller are short listed, another portion feels that the institutionalists will win, people like Armen Alchian, Oliver Williamson, Jean Tirole, Oliver Hart, Gene Grossman, John Moore. The first two are the founders of the New Institutional Economics, while the last three have been instrumental in developing the incomplete contract theory, and Jean Tirole is just a genius in the field who will be recognized sooner or later.

By bet is still on Eugene Fama, Kenneth French and Richard Thaler, but if Oliver Williamson or Armen Alchian wins, I'd be very very happy too!

The Divide Among Multi Handed Economists

2008-10-10T18:42:00.003+08:00

Something has always bugged me. It seems too irresponsible and naive to classify economists by the usual left versus right argument, or intervention versus non-intervention. Instead, Paul Romer gives us an alternate and better way of dividing economists (via Greg Mankiw):

Debate among economists about the $700 billion Paulson plan reveals a deep divide between realists and fundamentalists.

To be more specific:

The financial crisis provoked three open letters to policy makers. Fundamentalists opposed the plan. Realists supported the plan or supported more discretionary powers for dealing with the crisis without endorsing any specific plan.

A quick look through the lists of economists who signed the various letters shows that the camps do not separate cleanly along the familiar lines of left-versus-right or active-versus-limited government. The key difference lies in the relative weight each side gives to formal models as opposed to judgment.

Fundamentalists have an unswerving faith in models. Policies should always be derived from the best available model. Data should be filtered through a model. If an observation does not fit within the context of a model, it should be excluded from consideration.

Realists are more conscious of the limits of models and more comfortable with a division of labor between the researcher who improves the models and the clinician who makes policy decisions. They recognize that the power of models comes precisely from a commitment to abstraction that filters out potentially important complexity. They believe that useful evidence can accumulate with direct experience as well as through the research process of testing and refining models. They believe that researchers should consider the possibility that the fault lies with the model when its predictions diverge from clinical judgment and that policies should draw on both sources of evidence.

Well, so who is right!? The answer is not clear:

Many times, the confidence fundamentalists have had in abstract models turned out to be well founded and the objections raised by realists who were more focused on details were misplaced. The fundamentalists were right that an airline industry could still function even if airlines could set their own fares; that people could still talk to each other even if they purchased phone service from different companies. The realists pointed to all the complicated details that arise in such markets, details that simple models could not capture. Fundamentalists, correctly, ignored the detail and pushed prescriptions based on the textbook model of competition.

Other times, the models are missing something that is too important. In the study of macroeconomic fluctuations, real business cycle theorists and their descendants, the dynamic stochastic general equilibrium modelers, are the quintessential fundamentalists. Their models are a useful way to make research progress, but in macroeconomic policy making, the great depression, which these models cannot explain, is a decisive data point warning us that the models are incomplete and have to be supplemented by clinical judgment.

In my humble opinion, a level of abstraction is important for economics. There are a plethora of variables that affect an economic outcome, and the relationship between each variable is also too complicated to trace. Economic models are important for policy makers who wish to make decisive and quick judgements on the issues at hand. A model that is too complicated shadows the one or two variables that are truly important for making the right decisions. In other words, abstract models allow economists to focus on the things that matter.

However, economic models are inherently different from the real economy. Though the models are quite right under certain given conditions, changes in the environment that is ignored by the models can lead to incorrect predictions. As a result, on the other hand, economists also have to be wary of the limitations of these models. For too long, financial economists have downplayed the role of default risks, and risk managers have thus focused too much on market risks, leading to an underestimate in the amount of risk their assets are exposed to. The primary reason for this is their belief in models.

As to the 700 billion bail out plan... I have no idea whether or not it is a good idea. But to rejuvenate the economy with a large dose of liquidity is a good thing, and probably the only way to reignite the confidence in investors again. The question though, is how should we use this 700 billion dollar wisely? Where does this money go and how?

Debunking conventional wisdon: China's Pollution

2008-10-08T21:40:00.007+08:00

A surpising new finding:

A detailed analysis of powerplants in China by MIT researchers debunks the widespread notion that outmoded energy technology or the utter absence of government regulation is to blame for that country's notorious air-pollution problems. The real issue, the study found, involves complicated interactions
between new market forces, new commercial pressures and new types of governmental regulation.

........ One of the most surprising findings was that "the kinds of technology currently being adopted in China are not cheap. They're not buying junk, and in some cases the plants are employing state-of-the-art technology."

And furthermore, Joe Biden was right about China burning dirty coal:

The findings suggest that emissions levels from Chinese powerplants, he said, "depend almost entirely on the quality of the coal they use. When they're hit by price spikes, they buy low-grade coal."

But there is hope!:

In some respects, the situation is more amenable to change than many people had assumed, Steinfeld said. With expanding regulatory capacity and increasingly sophisticated efforts to regulate through market-friendly pricing mechanisms, reformers could achieve change relatively quickly, he said. "At least the technology -- the physical infrastructure of China's energy system -- is not an impediment," he said. Indeed, it can ultimately prove a key asset for achieving better environmental outcomes.

That is what I call a bargain!

2008-10-07T19:38:00.002+08:00

A woman buys a house on eBay for $1.75

I guess things are really bad right now.

If the world were allowed to vote....

2008-10-03T17:04:00.003+08:00

If the whole world were allowed to vote for the president of the United States, Obama would win hands down! The only country that is leaning for McCain is Macedonia.

Taiwan supports Obama 78% to 22%, while China supports Obama 81% to 19%.

Economists for Obama

2008-09-30T00:27:00.004+08:00

I like this blog alot!

This list is most impressive!

Economic policy advisors:

Jason Furman (director of economic policy)
Austan Goolsbee (senior economic policy advisor), University of Chicago tax policy expert

Karen Kornbluh (policy director)

David Cutler, Harvard health policy expert

Jeff Liebman, Harvard welfare expert

Michael Froman, Citigroup executive

Daniel Tarullo, Georgetown law professor

David Romer, Berkeley macroeconomist

Christina Romer, Berkeley economic historian

Richard Thaler, University of Chicago behavioral finance expert

Robert Rubin, former Treasury Secretary

Larry Summers, former Treasury Secretary

Alan Blinder, former Vice-chairman of the Federal Reserve

Jared Bernstein, Economic Policy Institute labor economist

James Galbraith, University of Texas macroeconomist

Paul Volcker, Chairman of the Federal Reserve 1979-1987

Laura Tyson, Berkeley international economist, Bill Clinton economic adviser

Robert Reich, Berkeley public policy professor, former Secretary of Labor

Peter Henry, Stanford international economist

Gene Sperling, former White House economic adviser

Other prominent economists who support Obama:

Brad Delong, Berkeley macroeconomist

Joseph Stiglitz, 2001 Nobel laureate

Edmund Phelps, 2006 Nobel laureate

Ray Fair, Yale macroeconomist

Dan McFadden, 2000 Nobel laureate

Robert Solow, 1987 Nobel laureate

Prominent finance people who support Obama:(not actually economists)

William Donaldson, Securities and Exchange Commission (SEC) Chair 2003-05

Arthur Levitt, SEC chair 1993-2001

David Ruder, SEC chair 1987-1989

Warren Buffet, investor, richest person in world

Latest Nobel Buzz: Nobel Prize Prediction 2008

2008-09-29T22:44:00.002+08:00

An article has boldly predicted that an economist of Indian decent will probably win the Nobel Prize this year. Their choices are;

1. Jagdish Bhagwati - International trade specialist
2. Avinash Dixit - Game theory, IO, International trade, .......
3. Partha Dasgupta - Development economics, environmental economics

I cannot say that I am familiar with their work, or even the fields that they have revolutionized, so I can't comment on this list. However, I would say that if Dixit wins, it probably won't be for his contributions to game theory or industrial organization, since there are plenty of other guys who have had more impact on these two fields.

The article continues to list some more economists who have a chance:
Peter Diamond - Macroeconomic titan
Dale Mortensen - search and matching theory in frictional unemployment
Christopher Pissarides - Again, search theory, unemployment
Elhanan Helpman - International trade titan
Robert Barro - Macroeconomic titan
Paul Krugman - New trade theory
Paul Romer - Endogenous Growth Theory
Gene Grossman - Work on asymmetric information (probably for incomplete contracts too)
Eugene Fama - Market Efficiency Hypothesis

I think all these guys deserve a prize. But in light of the recent financial turmoil, and the lack of common understanding that economists have displayed in response to this catastrophe, I think we should award the prize to Eugene Fama (and Kenneth French), and Richard Thaler (I really do not know why he is not mentioned more often). This award would be a joyful occasion to both sides of the profession: those who believe in government intervention and those who do not.

I studies finance during college, and I know how Fama's efficiency argument has been a basis for much of the deregulation argument (not to mention a whole bulk of finance theory is based on it), while Thaler's contributions to behavioral finance has led a whole new revolution on making economics more about homo sapiens than it is about homo economicus. In my opinion, both deserve the prize, and what better time to give the prize to them than now!

The Bailout Plan: Joker Style

2008-09-27T11:19:00.004+08:00

I think I will make a summary of what happened with the financial crisis, and the policy advice of some of the more pominent economists as soon as possible. It just doesn't seem right for my blog to be silent on this issue.

Best Graduate Schools in Economics

2008-09-22T20:05:00.002+08:00

The full list is here.

And for the finance people, this is a list for finance.

Hillary Would be Proud of

2008-09-20T18:33:00.000+08:00

Rwanda!

Rwanda will be the first country where women will outnumber men in parliament.

Pictures from Beijing-Hsinchu Economic Conference

2008-09-20T17:34:00.020+08:00

新竹清大的黃春興老師

新竹清大的吳易樺學長

北京清大的羅偉卿學長

新竹清大的龍歌

下午討論會的主持人，俞欣榮

新竹清大的老師群

俞哥聽問題

新竹清大的許峰銘

我口渴了，馬拉松式的報告

北京清大的張賀與孫靈菲

北京清大的單淼 (有人念成ㄉㄢ水)

余沛成: 我都聽不懂。俞欣榮: 攝影師在&*%##&^%個##$%#阿?

北京清大的趙燕琛

新竹清大的邱詩詠學姊

大合照!

How to Explain Inflation to Your Wife

2008-09-17T15:29:00.003+08:00

Very SEXIST, but good!

'When we married, you measured 36-24-36. Now you’re 42-42-42. There’s more of you, but you are not worth as much.'

Just a Correlation!

2008-09-14T12:54:00.003+08:00

芝加哥大學經濟教授 Casey Mulligan 說選共和黨的話，男女平均收入會比較接近。也就是說，若你希望男女平等的話，你就應該支持共和黨當選。但這是真的嗎?

有一個部落格願意解釋這個現象:

Given the Republicans' strong anti-equality record, Mulligan's finding that Republican presidents increase pay equity for women surely demands an explanation. What is the causal mechanism here? But curiously, Mulligan is entirely silent on this point. He offers no explanation for these findings -- not even the usual blather about how Republicans let the magic of the market do its thing.

.....It's not that Republican economic policies help women all that much. It's that they hurt the working class, especially working class men. A lot.

也就是說，不是女性的薪資上漲，而是男性的薪資在共和黨的執政下被往下壓縮了。

近幾年經濟學時常只是提供一個有趣的 correlation 而沒有做太多的解釋。這不是一個好現象!

What are Commercials Trying to Tell Us?

2008-09-13T16:11:00.004+08:00

Even though 20 years ago, economists have rendered advertising content meaningless, since its sole purpose is to look flashy and act as a signal of quality, I really think that analyzing advertising content is an important issue in industrial organization and the future of microeconomics.

Think about this: I can tell you that my house is 'huge', or I can instead tell you exact number of acres. Which one would you rather hear? However, which one would arouse interest?

Just my humble opinion.

First Lesson in Economics

2008-09-12T20:04:00.002+08:00

"It is through exchange that difference becomes a blessing, not a curse."

This should be the first lesson in economics. And as pointed out by The Austrian Economists, "Have the benefits of the specialization and exchange ever been presented more concisely and beautifully than in that one sentence?"

開學前最夯的學術會議

2008-08-31T23:08:00.003+08:00

首屆兩岸清華經濟論壇:

A Check Up from the Neck Up

2008-08-31T13:00:00.004+08:00

馬侃前幾天震驚了美國政壇，選了阿拉斯加的女州長，培林，當他的副手。這選擇有許多讓人匪夷所思的地方:

1. 阿拉斯加已經是共和黨的大本營了。難道馬侃不想拉攏一些中間選民嗎?

2. 馬侃最喜歡講歐巴馬缺少經驗。他卻選擇了一位比歐巴馬還沒有經驗的人當副手。才當州長兩年，之前是做一位人口不到9000的州長。他以後想要用什麼來攻擊歐巴馬?

3. 培林被懷疑濫用職權目前正在接受調查。這故事在這裡:

Sarah Palin’s sister Molly married a guy named Mike Wooten who is an Alaska State Trooper. Mike and Molly had a rocky marriage. When the marriage broke up, there was a bitter custody fight that is still ongoing. During the custody investigation, all sorts of things were brought up about Wooten including the fact that he had illegally shot a moose (yes folks this is Alaska), driven drunk, and used a taser (on the test setting, he reminds us) on his 11-year old stepson, who supposedly had asked to see what it felt like. While Wooten has turned out to be a less than stellar figure, the fact that Palin’s father accompanied him on the infamous moose hunt, and that many of the dozens of charges brought up by the Palin family happened long before they were ever reported smacked of desperate custody fight. Wooten’s story is that he was
basically stalked by the family.

After all this, Wooten was investigated and disciplined on two counts and allowed to kept his position with the troopers. Enter Walt Monegan, Palin’s appointed new chief of the Department of Public Safety and head of the troopers. Monegan was beloved by the troopers, did a bang-up job with minimal funding and suddenly got axed. Palin was out of town and Monegan got "offered another job” (aka fired) with no explanation to Alaskans. Pressure was put on the governor to give details, because rumors started to swirl around the fact that the highly respected Monegan was fired because he refused to fire the aforementioned Mike Wooten. Palin vehemently denied ever talking to Monegan or pressuring Monegan in any way to fire Wooten, or that anyone on her staff did. Over the weeks it has come out that not only was pressure applied, there were literally dozens of conversations in which pressure was applied to fire him. Monegan has testified to this fact, spurring an ongoing investigation by the Alaska state legislature. But, before this investigation got underway, Palin sent the Alaska State Attorney General out to do some investigative work of his own so she could find out in advance what the real investigation was going to find. (No, I’m not making this up). The AG interviewed several people, unbeknownst to the actual appointed investigator or the Legislature! Palin’s investigation of herself uncovered a recorded phone call retained by the Alaska State Troopers from Frank Bailey, a Palin underling, putting pressure on a trooper about the Wooten non-firing. Todd Palin (governor’s husband) even talked to Monegan himself in Palin’s office while she was away. Bailey is now on paid administrative leave.

As if this weren’t enough, Monegan’s appointed replacement Chuck Kopp, turns out to have been the center of his own little scandal. He received a letter of reprimand and was reassigned after sexual harrassment allegations by a former coworker who didn’t like all the unwanted kissing and hugging in the office. Was he vetted? Obviously not. When he was questioned about all this, his comment was that no one had asked him and he thought they all knew. Kopp, defiant, still claimed to have done nothing wrong and said to the press that there was no way he was stepping down from his new position. Twenty four hours later, he stepped down. Later it was uncovered that he received a $10,000 severance package for his two weeks on the job from Palin. Monegan got nothing.

馬侃選她有一個原因是因為她沒有長期待在華府，有她在，馬侃的改革決心看起來會比較有說服力。但是，看樣子培林跟一般的政客也沒有差多少。所以選她當副手馬侃真能說服大家，這個組合能夠給美國帶來重大的改革嗎?

4. 更恐怖的是，馬侃在選她之前只有跟培林見過一次面:

McCain really doesn't know that much about Palin, either. He met her once in February. He interviewed her as part of the vetting process...and that's it. He never worked with her.

而且她不知道培林正在接少調查!!!!

A very reliable source overheard Republican spokesperson McHugh Pierre state TODAY that he had spoken to the McCain Campaign. They are coming to Alaska tomorrow to check out the "Troopergate" investigation.

In other words, THEY DID NOT DO SO PROPERLY AHEAD OF TIME.

喔天阿! 馬侃到底在想什麼阿!?

總結以上的一些疑問，我們可以發現兩件事: 1)馬侃現在很緊張，想要用一個女的副手拉一些人氣。2)馬侃的判斷有問題。沒有看過所有的證據在做決定，也沒有跟其他人先討論。

從馬侃這一次選副手的表現來看，她以前批評歐巴馬簡直是 "一百步笑五十步"。這選舉已經提前結束了!

I'm so happy! I got the bronze medal!

2008-08-28T16:00:00.002+08:00

我們這一屆奧運的7金夢破碎，換來了4枚銅牌。這對國人來說也許會蠻失望的，但是對選手而言呢? Dan Ariely，現在最有名的行為經濟學家之一，在他的部落格寫:

What do you think? Who is likely to experience more regret? Someone who won the silver medal in the Olympics, or someone who won the bronze medal in the Olympics?
In one study Bob Willingham took thousands of photographs of athletes in the seconds after they had won or lost a medal. Next, David Matsumoto then coded the photographs according to the athletes’ expressions.

What did they find? bronze-medal winners looked nearly as happy as the winners of the gold medal, whereas the expressions of the silver medalists more closely resembled the athletes who placed fifth.
Silver medalists at the Olympics seem to perform what we call an upward comparison — they compare themselves against someone better off than them. Bronze medalists seem to perform downward comparison — they tend to compare themselves with people who did worse.

所以若論我們選手的福利的話，這銅牌可是與金牌等價阿!!

The Amazing Bolt!

2008-08-28T15:26:00.004+08:00

How good is Bolt? This graphic illustration tell us just how lucky we are to witness one of the most amazing feats of the human body.

給學弟妹的

2008-08-26T01:27:00.001+08:00

To 學弟妹:

若你在閱讀這一篇文章，就表示你即將要成為研究生。這是什麼意思呢? 當經濟的研究生要幹什麼呢? 你們即將面臨哪一些挑戰呢? 這一篇文章將分成兩大部分: “研究生應有的態度” 及 “即將面臨的挑戰”。

研究生要幹什麼?

課堂裡的生活
顧名思義，研究生就是要做研究 (你不會以為只要念好手邊的書就好了吧?)。當然，你們也會修許多課，但是這一些課都是為你們未來作研究而開的。所以這一些課都會有考試，但是時常都是take home exam，其目的在培養各位自己找答案的能力。也因為如此，所以各位修這一些課的態度也要有別與以往大學時追求考試高分或是報告高分的態度。各位要記得，修這一些課是希望各位具備作研究的能力，因此你們主要的目標應該是要如何靈活的應用你們在課堂裡所學的東西，及這一些東西有沒有寫論文的空間。如此一來，你們會需要駕馭老師所教的同時也會需要主動到圖書館找尋相關的資料以取得更全面的理解。各位只要記住，念研究所要培養自己找尋答案與學習的能力。

當然，自己悶著頭在圖書館念書也不是辦法。一本一千多頁的原文書往往不是尋找答案最好的開端。最好的起頭時常是自己身邊的同學，學長及老師。研究所的同學要彼此互相學習與交流。各位入學不久後，就會發現每一位同學在經濟領域裡都有不同的專長，因此今天你若有問題，往往可以從同學身上摸著頭緒。哪一天同學問到你懂的問題，你也要很主動的題供一些意見，因為研究生彼此的關係就是有來有往，一起向上進步的狀態。系上的老師也是很棒的寶庫。老師也都很樂意分享他們所知道的一些東西。但是老師與同學也時常只能給一個很粗略的答案，因此各位可以請老師或同學推薦書或是論文以便自己取經。因此，各位要謹記，不管你們是問老師或是問同學或學長，你們的態度應該不是要問答案，而是應該要問尋找答案的途徑。

課堂外的生活
我不會推薦各位看哪一部電影 (黑暗騎士很好看，我看了兩遍!)，我也不會跟各位說要怎麼分配自己的時間，或是各位應該修幾學分或是可不可以打工 (有一位很不錯的經濟學家，Kevin Murphy，就是從打工學習到很多經濟學)。我只能跟各位說，適當的休息很重要，但是經濟學的靈感來源千奇百怪，各位要時常胡思亂想。例如，各位若有看奧運，可能會發現中華職棒打到第五名也可以拿錢，而中國的運動選手只有拿金牌才有奨金可拿。各位可以想想，這兩種不同的獎勵方式會如何影響選手的態度與表現呢? 或是若各位有注意女子體操可能有耳聞中國體操選手年紀不到16歲的傳聞 (奧運選手一定要滿16歲才能參賽)，各位也可以想一想有什麼辦法可以證明這幾個中國女子體操選手年齡不及16歲?

我的重點來了! 雖然經濟學家沒有實驗室，但是我們有更好的工作場所: 整個社會就是我們的playground。要隨時保持好奇心，有時候最愚蠢的問題卻是經濟學突破的開端 (Michael Spence就是問說 “為何要去學校念書?” 而最終得了諾貝爾獎)。因此”思索”經濟學是很重要的!

然而想出一個答案還不夠，各位還要把它寫出來，把你的經濟邏輯清楚的表達出來以便其他人能理解。有的時候寫一寫才發現自己想的答案是錯的，或是寫一寫才發現自己的論點了無新意，不值得追究。一個想法的好壞要把它寫出來才能印證。這時候各位又會遇到一個問題，

你已經把一個想法清楚的在白紙黑字上表達出來了，整個邏輯也說的通，但是你要如何判斷經濟故事豐富不豐富，或是你的想法有沒有貢獻? 簡而言知，就是要如何判斷什麼是好的想法? 這就要看各位有沒有時常閱讀書或論文。看書或論文可以幫我們培養”經濟學的品味”。任何人都可以做數學模型，任何人都可以掰一個經濟故事，但是要如何做出一個好的研究就要多看一些大師的作品。剛剛開始看的時候，大概只能看得懂一點點，但是看多了之後就可以看出一些端倪，各位也會發現自己的能力逐漸提升，想法也越來越精緻，寫出來的東西可看性也變高了許多。更重要的是你們也會培養出經濟學的品味，可以判斷自己做出來的東西是好是壞。

茶餘飯後，你也可以把你寫的東西跟你的同學或老師分享並徵求他們的意見，你也可以問他們看哪一些書或論文來幫助你發展你的想法。一個想法要多跟他人討論，若你的同學或老師都聽不懂或看不懂你寫的東西，那你可能就要換一個題目。但也很有可能是你不會”推銷”你的想法!

同樣的想法有可能因為包裝的好壞而受到不同的待遇。這東西很抽象，我自己也非常不懂。每一個想法都有一個經濟的故事在背後支撐他，你要如何把你的經濟故事弄得有趣，或是有影響力是很重要的。各位除了多看一些大師的論文之外，也可以多參加我們系上星期二下午的研討會，可以聽聽看其他教授是如何present他們的論點。

因此，課堂外的時間，各位要多”想”，”寫”，”讀”，”討論”及”聽”經濟學。

念經濟研究所會面臨什麼挑戰?

數學
這是最常被提及的(問題)挑戰。許多學弟妹即將面臨所謂的”語言障礙”。沒有錯，數學在經濟學沒有什麼神聖的地位，它不像在物理學裡可以幫我們解開宇宙的秘密。它在經濟學裡所扮演的角色只是一個語言而已! 經濟學家喜歡用數學來傳達自己的想法因為它比較嚴謹。若我們今天不使用數學，我們的答案會異想天開，變的沒有確切的依據，容易偏離經濟思維的軸心 (這軸心就是人會作出理性的選擇)。正是因為數學能清楚的表達出經濟邏輯，要成為經濟學家就必須熟習這語言才能讓其他人接受你的想法。

在美國開學前，經濟系的研究生都要上所謂的 “math camp”。可以從該堂課中學習到念經濟應具備的數學能力。台灣的經濟研究所沒有這種課，所以各位要自己補強這一方面的能力。許多人將個經，總經與計量所用到的數學統稱為經濟數學。然而，這不是一個理想的分類法，因為各位隨便拿一本經濟數學的課本會很難找到計量相關的數學。一般所稱的經濟數學都是在討論最適化的方法，也就是optimization，一般而言，微積分基礎好的人理解這不會有太大的問題。但是計量經濟都在討論資料的處理，若有念過數理統計者將較容易理解。

若要加強數學，可以買一本經濟數學的書或是一本數理統計的課本，也可以旁聽清大所開的一些數學課。清大數學系是全台灣最有名的數學研究機構之一，大家可以在這兩年間，把握機會多修一些數學系所的課，收益良多。那要聽哪一些課，買哪一些書呢? Greg Mankiw 有推薦經濟系的學生修下列的課程:

1. Calculus – 微積分
2. Linear Algebra – 線性代數
3. Multivariable Calculus – 多變數微積分
4. Real Analysis – 實數分析 (這在清大只有開給研究生的水平，修前請三思)
5. Probability Theory – 機率論
6. Mathematical Statistics – 數理統計 (可以考慮修計財系，鐘經樊老師的課)
7. Game Theory – 賽局理論 (任何想要研究個體經濟學的人一定要修)
8. Differential Equations – 微分方程 (修ODE就好)

若大家覺得考試壓力很大，可以考慮旁聽。我個人曾修以上所有的課程除了微分方程。(但我實分析被當!) 修過這一些課程對理解課程內容與論文的數學模型有非常大的幫助。

大家若有空也可以到圖書館參考下列的書籍。這一些書對我來說是有很大的幫助。至今我都時常放在我身邊，因為我時常會需要參考它:

數學:
1. Elementary Classical Analysis by Jerrold E. Marsden and Michael J. Hoffman
2. Principles of Mathematical Analysis by Walter Rudin

經濟數學:
1. Optimization in Economic Theory by Avinash Dixit
2. Mathematics for Economists by Carl P. Simon and Lawrence E. Blume

數理統計:
1. Introduction to Mathematical Statistics by Hogg, Craig and McKean
2. Introduction to Statistics and Econometrics by Takeshi Amemiya

其實有一些經濟學課本後面的附錄中也有一部分是講經濟數學的，內容也都相當豐富。我個人最喜歡 Geoffrey Jehle and Philip Reny 所寫的 Advanced Microeconomic Theory 裡的數學附錄。暑假剩下幾周的時間不妨從這一本書的附錄開始複習。

經濟
大家是來念經濟學的，但是時常會覺得自己的精力和時間都奉獻給數學了。這也難免，畢竟要學會寫程式之前必須要先搞懂程式語言。想要看一本得過普立茲獎的書之前，最起碼需要看得懂英文。然而，我發現許多人看原文書時，會鑽研那一本書中的文法，每一個不懂的單字都查字典，每一頁都圖滿了密密麻麻的中文筆跡。這種態度是很好的! 可惜的是，時常會因為這樣而忘記了書的情結或內容，根本不記得書到底在寫什麼了! 念經濟學也時常會這樣。有時會很興奮的在那邊偏微分，但是卻完全忘記我們為何要這樣作。所以當你看到一個數學式的時候，你不僅要確認他導出來沒有問題，更重要的是你要理解他經濟含意。有的時候看多了就自然會明白一些數學式子背後的意義。更厲害的人，給他一個經濟問題，他不用數學也可以一步一步的推敲結論。而他的邏輯脈絡是可以一步一步的用數學表示。這就是所謂的經濟直覺。這是所有經濟學家都在尋求的。我個人發覺有一個方法是可以很快的培養這種直覺: 多看經濟的書。

看課本或上課時常會感到疲勞或乏味，漸漸的就失去對經濟學的熱忱，因為課本或課堂的內容有時過於技術性。我個人喜歡看經濟的書來培養經濟直覺，因為看這些書不僅可以學到許多大師是如何思考經濟問題，更可以培養對經濟的熱忱 (因為裡面沒有過多的技術細節)。以下我推薦幾本我喜歡的書給各位:

1. “The Armchair Economist” by Steven Landsburg – 若只有時間閱讀一本，就看這一本。
2. “The Logic of Life” by Tim Harford – 兩個月前才看完的，最後面有介紹到民主的形成，非常精彩!
3. “The Undercover Economist” by Tim Harford – 個經教到差別取價時，要閱讀第三章!
4. “Freakonomics” by Steven Levitt and Stephen Dubner – 想要了解一下經濟思維的另類應用，就一定要看，我有作者的簽名喔!
5. “The Strategy of Conflict” by Thomas Schelling – 賽局的經典著作之一，將賽局 “人性” 化了。我有作者的簽名!
6. “Thinking Strategically” by Avinash Dixit and Barry Nalebuff – 想認識賽局理論的思考方式，但是又怕數學，這本必看。
7. “Knowledge and the Wealth of Nations” by David Warsh – 經濟故事書。裡面發生的事都是真實故事，故事男主角，Paul Romer，是被譽為鐵定能拿諾貝爾獎的經濟學家。各位會念到的內生性經濟成長模型就是它所提出的。
8. “More Sex is Safer Sex” by Steven Landsburg – 書的內容將外部性的一些驚人結果描述的很清楚。
9. “The Economics of Life” by Gary Becker – 裡面探討的東西偏難，但是這位諾貝爾獎得主就是有辦法化繁為簡。建議對經濟學有一點認識時再看。
10. “When Genius Failed” by Roger Lowenstein – 講述幾位華爾街最聰明的頭腦，最後差一點把整個美國經濟給搞砸。不要念計財! 開玩笑啦!
11. “Defending the Undefendable” by Walter Block – 若你心臟夠強就看，因為它有很多論點你看了可能會生氣。但是這本書是好書。
12. “The Making of Modern Economics” by Mark Skousen – 必讀。一位念經濟的人一定要了解經濟學從亞當斯密斯那看不見的手開始，到現在理論的演變過程。這本書很多故事!

清大是一間很棒的學校，各位不要排斥與其他系所交流 (我跟資工的同學交流發現我所學的東西在他們那邊可以應用到一些問題上)，各位也不要排斥學習其它新的事物 (我跟不同系所的朋友聊天總是學到一堆有趣的知識)。當研究生就是能學多少就學多少。我相信保持這樣的態度會讓你如魚得水，在清大過的非常充實自在。

Cheers!

余沛成

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