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NullVoid » 2006 » April NullVoid » 2006 » April

Archive for April, 2006

Force is with you, but you are not a jedi yet

Thursday, April 27th, 2006 -- By ET

In preparation for my thesis defense, I spend some time to study how to make effective slides, and this website came to my attention:

Presentation Zen

It is painfully amuzing to read the posts, some comments are quite thoughtful too.

In this post, he compares the Evil (Darth) with the Wise (Yoda)



I may post some of my slides here later, time spent on learning presentation skills is time well spent!

- Wisedom is with me, but I am not a PHD yet.  :-)


Monday, April 24th, 2006 -- By Jade

奇怪得很, 小薇薇的脑门上 (只是在她的小额头上, 别处没有) 总有一点怪怪的味道. 先要声明一下, 薇薇小姐隔一天洗一次澡, 每天都要擦香香.  我先是觉得有点虾酱得味道. 让小豆闻下, 他也觉得是有点奇怪, 为什么会有这个怪怪得味道呢? 断言道一定是我亲她脑门亲出得口水味. 我立刻反对: 胡说, 那我亲了她的小胖脸, 怎么没有这个味呢? 百思不得解中. 味道还在继续中. 今天中午做菜, 用倒了四川豆瓣酱. 豆瓣酱一下锅, 我和小豆都闻倒了一阵熟悉得味道: 没错, 就是这个味倒. 薇薇脑门上的味道. 呵呵, 原来不是虾酱味道, 是豆瓣酱味道. 小豆又断言道一定是我怀孕时吃老姐找人带来的四川辣豆瓣酱白菜豆腐乳吃多了. 我冤啊. 可是这个味道真的很奇快哦. (嘻嘻, 我现在还觉得挺好闻哩)

薇薇一如既往的是个好宝宝, 吃的好, 睡的好, 长的好. 对了, 她很能说话. 要是又爸爸妈妈陪着说最好了, 要是爸爸妈妈没空的话, 她就会自言自语: 哦, 哦, 啊, 啊的对着她头顶上的小紫象说上个十几二十分钟, 有时还呵呵的笑两声. 薇薇现在吃手也不费劲了. 手到擒来, 吃完左手, 吃右手, 然后再左手托着右手吃, 右手托着左手吃, 最后两只手一起吃. 吃得津津有味, 经常不顾自己美女的身份, 吃出很大的声音来. 她还是一个越来越爱笑的宝宝, 经常看着爸爸妈妈姐姐咧开小嘴大乐, 那个嘴啊, 真是笑着咧道耳朵边了. 看着她乐, 我也就立刻觉得带宝宝一点也不辛苦, 生活真得太美好了, 然后和她一起咧着嘴傻乐. 娘儿两一起傻乐得样子真的很好笑啊.  



Friday, April 21st, 2006 -- By ET

I went to Washington DC early this week to participate an NBER conference on Innovation Policy and Economy, there are a lot of government officials participating.  A professor from Northwestern (DANIEL DIERMEIER, he is a great presenter, I liked his slides so much) quoted Rumsfeld’s famous sentence on "known knowns and unknown unknowns".

"Reports that say that something hasn’t happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns — the ones we don’t know we don’t know." 

That was funny, and is quite true. 

His comment on Iraq’s Mass destruction weapons is also hilarious:


"the absence of evidence is not the evidence of absence"


To me, these are very good guidance to research!  In econometrics, known knowns are probably those observables, known unknowns are usually captured by the error term.  The big headache is unknown unknowns which can give us headache of missing variable issues.

The second quote tells us that insignificance of a regression does not mean there is no relationship between the dependent and independent variables.

Oh, here is another one:

"I don’t know what the facts are but somebody’s certainly going to sit down with him and find out what he knows that they may not know, and make sure he knows what they know that he may not know."

Anyone who took a course in game theory should ring a bell here on the definition of common knowledge: I know you know, and you know that I know you know, I know that you know I know you know, … …


Simply hilarious 


Saturday, April 15th, 2006 -- By Jade

好不容易想省$10, 又没省成. 今天偶拿着toy’s r us 的 coupon乐颠颠地让lg带偶门一家去买萱萱的scooterr和薇薇的diaper. 想不倒啊, 想不到. 我们一家老小先到了south bay的toy’s r us, 竟然关门大吉乐, 那再去fresh pond的吧, 竟然也关了. 要按平时, 我一郁闷就打道回府了. 可是今天不行啊, 偶有coupon啊, 我下定决心, 要省下这$10, 连哄待威胁的让lg开去everett的baby’s r s. 萱萱还是在车上哼哼:妈妈, 我要play dough, 我要play dough…….dough……….. 路上的风景还真的不错. 毕竟是春天来了, 四处春色啊. 这charles 河边, 更是春花烂漫, 美啊……我正美着呢, 嘴里一边跟着CD哼着不成调的小曲, 一边和 lg 聊聊天, 有时还要对萱萱说: 就去给你买paly dough. 总之心情一派 大好. 可是, 突然, 车子很大声的哗啦哗啦的响起来了, 怎么回事, 车坏了? 不会这么倒霉吧? 唉! 还就是这么倒霉. 不一会儿, 咣当一声, 不知道车上掉了个什么下来. 小豆一脸严肃的说: 车开不了了, 然后把车靠边停了, 下车去看了. 我刚才大好的心情一下子完蛋了. 萱萱还在说: 妈妈, 去买play dough….. "小姐, 咱能回家就不错了!@#$%^^^%*&" 正在给大小姐解释为什么不能买play dough的时候, 小豆手里举着个铁的东西从车底下爬出了. 也不知道什么东西掉下来了. 唉!!!!!!!!!!! 只好回家了, 好在车还能凑合开. coupon也没用成, 钱也没省成, 还得去修车. 今天怎么这么背呢? 明明大好得天气. 唉! coupon 明天就过期了.

Permanent Domain Name

Saturday, April 15th, 2006 -- By ET

A friend asked about the future of this blog after I leave MIT. 

I’ll try to get the old domain name still working http://mikezhang.com, but I may not have so much freedom to maintain the server any more.

So please change the book mark to  http://mikezhang.com it is fairly simple to remember.

I would imagine posting more interesting ideas in the future.  For now, I need to prepare my thesis defense.


Thesis Defense

Saturday, April 15th, 2006 -- By ET

My thesis defense is finally scheduled.  Here is the announcement:


Name: Xiaoquan (Michael) Zhang

Date: May 1, 2006

Time: 2pm- 4pm

Location: E53-301 (Hermann Building – where Dewey Library located)


Title: Tapping into the Pulse of the Market: Essays on Marketing Implications of Information Flows



Erik Brynjolfsson, George and Sandi Schussel Professor of Management, Chair

John D.C. Little, Institute Professor

Chrysanthos (Chris) Dellarocas, Assistant Professor of Information Systems



As the Internet continues to penetrate consumer households, online marketing is getting increasingly important for firms. By adapting to online strategies, firms are blessed (or doomed) with a plethora of new business models. The information flows created in the process poses both opportunities and challenges for marketers. On one hand, information flows captured online are usually easier to be stored and processed, thus empowering firms to be better informed about the consumers or the market itself. On the other hand, how to use the information flows to make the correct managerial decisions is still a challenging task for managers and academics alike. My thesis studies the marketing implications of these information flows. Broad as the research question is, I focus on specific market settings. I adopt both analytical and empirical methodologies to study information flows in these markets. Overall, this dissertation concludes that information flows can engender new market mechanisms, can provide valuable information of unobservable market forces, and can be created to improve social welfare.


Essay 1: Innovation Incentives for Information Goods


Digital goods can be reproduced costlessly. Thus a price of zero would be economically-efficient for consumers. However, zero revenues would eliminate the economic incentives for creating such goods in the first place. We develop a novel mechanism which solves this dilemma by decoupling the price of digital goods from the payments to innovators while maintaining budget balance and incentive compatibility. It is not surprising to find that innovation incentives in our mechanism are improved relative to the zero-price approach often favored by content consumers. However, it is surprising to find that the incentives are also substantially better than those provided by the traditional system based on excludability and monopoly pricing which is often favored by content owners.


Essay 2: Edgeworth Cycles in Keyword Auctions


Search engines make a profit by auctioning off advertisement positions through keyword auctions. I examine the strategies taken by the advertisers. A game theoretical model suggests that the equilibrium bids should follow a cyclical pattern— "escalating" phases interconnected by "collapsing" phases — similar to a pattern of "Edgeworth Cycles" that was suggested by Edgeworth in a different context. I empirically test the validity of the theory.


Essay 3: The Lord of the Ratings


Third party reviews play an important role in many contexts where tangible attributes may not be enough to evaluate products or services. In this paper, I examine the impact of professional and amateur reviews on the box office performance of movies. I establish an econometrics framework to control for the interaction between unobservable quality of movies and the word-of-mouth diffusion process. The framework allows me to estimate the residual impact of online amateur reviews on the demand. The results show significant influence of the valence measure (star ratings) of online reviews. Interestingly, the volume measure (propensity to write) is not significant once quality is controlled, and the analysis suggests that the variance measure (disagreement) does not play a big role in the early weeks. The estimated influence of the valence measure implies that a one point increase in the valence measure can be associated with 4%-10% increase in the box office revenues.



MIT Thesis LaTeX Class for Essays

Friday, April 14th, 2006 -- By ET

An “Essay Class” for LATEX Preparation of MIT Thesis

Xiaoquan (Michael) Zhang


MIT Sloan School of Management

1 Introduction

I’ll make this a very short (but hopefully very useful) document, to do this, I assume you know the basics of LATEX. You may find many resources on the Internet to learn LATEX. A good place to start is: http://web.mit.edu/olh/Latex/thes-latex.html

From the above website, you know that MIT offers a Template for thesis. The webpage has detailed instructions on obtaining it.

The template is inherited from the common base class “report.cls”. And it generates very elegant outputs to meet the requirements for thesis.

However, the template is written with a book-type thesis in mind, people writing an essay-type thesis may find it difficult to meet their needs. This document, and the companion class is here to rescue.

2 What’s wrong with mitthesis.cls?

Users are assumed to write chapters for this book, so document-wide counters all bear the chapter number.

For example, tables are named like “Table 3.4”, where “3” is the chapter number and “4” is the Table number. Similarly, sections are called “Section 5.2”, where “5” is actually the chapter number. This is ok in a book-type thesis, but does not make much sense in an essay-type thesis.

A second problem is that for each “Essay”, there are some required formats (like the chapter title page) that the class can not address.

A third problem is that the report class can not handle separate chapter bibliography files.

In the essayclass, I address all these problems.

3 Where to start?

First of all, you need to download the mitessay.cls file from my website. You can get the whole package in zipped formats, too. Then you need to follow my instruction below to modify your own chapter/essay files to be included in the main.tex file.

The MIT thesis website mentioned above gives you a lot of information on using the files mitthesis.cls, main.tex, cover.tex, etc. I skip these.

4 Step 1

Open mitessay.cls file with any text file editor, scroll down to change “Michael Zhang” to your own name, and “MIT Sloan School” to your own dept. (Sorry, I was lazy to create a variable to pass along the values. :-p)

Get, from your essays (I assume they are regular LATEX files), the preambles, and put them into the file called custzxq.sty, feel free to delete unnecessary packages already in there. The first package


is important, though. You need it to have chapter-specific references.

5 Step 2

Open your chapters, delete all the preambles till the title of the essay.

Do the following for all the essay files: at the beginning of the file, add two lines:



They help to reset the chapter number to be correct if you have Appendices in some of the papers. Change the number {1} to that corresponding to the chapter number. Since report.cls starts the chapters from 0, you need to subtract 1 from your real chapter number. So the example actually shows the modification needed for chapter 2.


\title{What Ever the Title Your Paper Has}


\chap{What Ever the Title Your Paper Has}

That was easy, isn’t it?

Now you need to send some environment variables BEFORE the \chap command.

Here is my list, you can change the text in the brackets.


Vel te lorem nostrud ullamcorper, ex iusto illum feugiat velit praesent blandit velit vel laoreet. Vel, ipsum qui nulla, zzril in accumsan tation qui vero at dolore – ullamcorper eros iusto, elit. Sed in te zzril consectetuer ad nulla aliquam dolore, nonummy, delenit sed wisi, te. Lobortis nonummy; dolore dignissim iusto facilisi, dignissim minim elit, veniam molestie consequat, at.



December, 2004



\textbf{Keywords:} some random keywords



This paper is based on joint work with …



This research has benefited from valuable comments from …


6 Step 3

Go to the end of the document, delete: \end{document}. You are all set to compile the files!

7 Conclusion

I introduce a new class for LATEX that provides one quick and dirty way to compile an essay-type thesis. This is done with quick hacks, feel free to modify it anyway you like. I hope this can be useful for other people. It may well save you a few hours (if you are good at LATEX) of time, and use that on your own important work. Enjoy!

Files to Download:

The file contains everything you need to get started

This document in PDF.

A sample file created with the mitessay class!

Golden Ring on the cannon

Thursday, April 13th, 2006 -- By Jade





好大的金戒指呀, 特此放照片一张留念 


Thursday, April 13th, 2006 -- By Jade


? ??, ???????????: ?????MIT???Cal Tech??? Fleming CANNON????. ?????????4????????Cal Tech???????. MIT ???Cal Tech ??????????, ??????????????, ?????, ??????????. ?????????????????, ???????" the only technolgoy institute ". ??, ??, ??????MIT?????, ????????????. ????????????????????????????. MIT????????Cal Tech???, ????????????24K??, ??MIT beaver(beaver ?MIT?????) ?????. ?????????, ?????????????4?, ??????????. ??????????Cal Tech ???????, ?????????.

?????Cal Tech?MIT??, ?????????????????.

Monday, April 10, 2006

"Where men are men, giants walk the earth, and the thundering herd is real."


Congratulations. You managed to move a three-ton cannon across the country without anyone knowing where it went. Although we applaud your prank, we would prefer to have the cannon back in Pasadena. It is on its way home now, but we have left you with a small gift — a token of remembrance.

We enjoyed our trip and the chance to defend our honor. Organizing ourselves in under a day, we deployed twenty-three Flems from home and seven alumni from the area. We came together to protect the pride of both our Hovse and Caltech.

This time, only Fleming Hovse had the pleasure of visiting your fine institution. But do not worry, all of Caltech will be back, and next time it will be a surprise.

Sincere regards,

Fleming Hovse
California Institute of Technology


Thursday, April 13th, 2006 -- By Jade

薇薇经常粉使劲地把小拳头塞到嘴里, 然后又粉使劲地在那里用小舌头舔呀舔, 偶尔抬起头来看看爸爸, 然后又继续舔呀舔. 小拳头上湿乎乎的. 姐姐看见了,一定会很快的拿一张纸巾来擦掉妹妹的口水, 并把妹妹的小手从嘴里强救出来, 还一定会说:"妹妹, 不许,不许吃手, 呀…….恶心". 然后爸爸就会说: 不能说恶心啊, 妹妹还小!@#$%%^&*.

有时候我抱着小薇薇坐在我腿上, 她就是不想坐, 然后就头和小身子使劲往后倒, 我只好把小东西放在床上让她自己玩一会儿. 有时我抱着她, 让她趴在我肩膀上, 想要把她从肩膀上抱起来, 她要是不想起, 就使劲往下趴, 还很有劲的样子, 让偶不得不让她接着趴在偶瘦弱的肩膀上.

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