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NullVoid » 2006 » November NullVoid » 2006 » November

Archive for November, 2006

book price

Thursday, November 30th, 2006 -- By ET

0521017157.jpg

In our university book store, I can find pretty much everything I want to find.

The shelf space is limited, so sometimes all books are not put on the shelf.   I was looking for two books:

1. Statistical Inference by Casella and Berger, and

2. Discrete choice methods with simulation by Ken Train

The first book sells for more than US$100 in the US, but only sells for HK$100 here (exchange rate: 1USD=7.8HKD).

The second book sells for US$25 in the US, but sells for HK$400 here.

Maybe the first book is a graduate course text book here, so it has quantity discount, but we all know text book demand is inelastic (meaning demand does not respond too much to changes in price), and quantity discount can not justify this huge difference.  I haven’t tried to get price quote for other books, but this is interesting.

Freakonomics and Long Tail

Thursday, November 30th, 2006 -- By ET

I have recently read two books: Freakonomics by Steven Levitt and The Long Tail by Chris Anderson.

They are both very relevant to my research interests and are unbelievably successful in the book stores. I found two English versions of Freakonomics and a translated Chinese version of the Long Tail in our university book store. So I went to the Central to buy an English version of the Long Tail in the IFC mall, I like the name of the book store, it’s called something like DYNAMICS or DYNAMO.

longtail.jpg
In the Long Tail book, Anderson gives many many examples to support one simple observation: niche market goods (obscure products) collectively can be as important as the mass market goods. This is not surprising as information technology enables the firms to almost costlessly add inventory. Many examples given in the book are induced by supply-side cost savings. Consumer search also contributed to the story, as it is easier to compare products and easier to find new niche-market products. (I got a set of SpaceWarp a few month ago, it is a toy that involves building up small roller-coasters on the table and let a metal ball to go around the tracks. The problem was that the toy was produced in the 80′s, and I do not have the manual. So I searched in Google, and found a complete manual and quite a number of websites discussing various innovative ways to play it.) Many blogs are following this book and keep repeating what was said in the book. With an innovative spirit, I’d like to pull the attention to possible inhibitors of the long tail. For example, although it is easier to search for obscure products, and by definition, there are a lot of them. “A wealth of information creates a poverty of attention” (H. Simon) So research needs to be done to study how to better match the consumer needs with the supply. I think the reason that no one studies it is that the topic is inter-disciplinary. Computer scientists may spend too much time on algorithms to improve the speed of matching, economists may spend more time to examine the social welfare gains from the matching, people in marketing care more about how firms should compete with other by introducing product differentiation, operations management people may be obsessed with how traditional supply-chain framework is affected. This observation promotes the idea of “business value of information”, that may not fit well to the traditional MIS paradigm. Fortunately, some researchers in the B-School is realizing this problem and in this year’s WISE (Workshop on Information Systems and Economics http://digital.mit.edu/wise2006) there is one session dedicated to the Long Tail. (I have a paper on Wikipedia with Feng Zhu of Harvard B School, it is an exciting one, too.)

Freakonomics.jpg

Comparing the two books, I generally like Freakonomics more, each chapter introduces a new topic and they are nicely fit into an overarching framework about the value of “Information”. Many interesting topics are covered, for example, how to detect cheating in sumo wrestling, how to detect teacher cheating in high schools, why African American kids are given distinctive black names, how Chicago drug dealers are similar to the clerks walking on wall street, etc. I especially like the chapter about how an India-born U Chicago-trained sociologist making friends with drug dealers and how economics can help to decipher the drug dealer’s account book. Maybe it’s time for me to go in disguise to join Taliban or Al Qaeda to study how they make use of information to organize their activities. My hunch tells me that they may be much more effective than even some big firms in their efficiency.

Finally, an interesting cartoon

a long tail-thumb.jpg

UPDATE:

I’d like to thank tkkoh’s pointer to the Rubinstein review of Freakonomics.  I read it and I don’t like his review:

1. Rubinstein is very sarcastic about the words such as “brilliant”, “clever” used in the book to describe Levitt and his methods.  I think Rubinstein is an accomplished academic, but that does not mean other people are any less brilliant.

2. Rubinstein obviously has some issues with Levitt’s math background.  Personally, I have been wondering how Levitt survived MIT with his math.  I still remember the feeling going out of the stats (Sara Ellison) and IO (Glenn Ellison) exams.  But from my reading of Levitt’s papers, he has really clever (sorry to use it again) ways of using stats to make his points.  I just wish there were more papers like this: use straightforward statistic tools to explain complex social phenomena.  If there is anything the economists should do (rather than repeating/re-discovering what Mathematicians have done decades or even centuries ago), it should be explaining things, or, although criticized by Rubinstein, justifying a viewpoint.

3. Rubinstein’s point about “re-finding” 2 million babies is not valid.  In any decent hospital in the US, the SSN is automatically processed when a child is born.

4. Rubinstein was so eager to find problems in a chapter title, that he contradicts himself.  In section 4, he first disagrees with Levitt (totally ignoring the other author, Dubner), who claims that “Who cheats, well, just about anyone, if the stakes are right.”  Then supports the exact claim by giving his own example: “In the few cases in which I (Rubinstein) conducted experimental research, I myself felt the pressure not to search further at a stage in which the experimental results went in my favor and to check findings seven times when they appeared not to support the assumptions I was sure were correct.”   Levitt’s argument is not that economists are any smarter than anyone else, his very point is that economists are not less likely to cheat than your grocer!

I believe this book will turn many kids into economists for the time being, or at least let them know the power of critical thinking. While I’m not sure if the society needs more economists, the second point certainly makes this book invaluable.

One last word about the Rubinstein review, reading this review reminds me reading referee’s report with which everyone in my profession is familiar.  I don’t understand why they derive such utility from pancaking those minor points and just ignore the great value underlying the innovative and creative works.

Some useful books on Bayesian Methods

Wednesday, November 29th, 2006 -- By ET

Tony Lancaster, HB139, L353, 2004
An Introduction to Modern Bayesian Econometrics

Jeff Gill, QA279.5, G55, 2004
Bayesian Methods: A Social and Behavioral Sciences Approach

Peter Rossi and Greg Allenby and Robert McCulloch, HF 5415.2, R675, 2005
Bayesian Statistics and Marketing

Dani Gamerman and Hedibert F. Lopes, QA 279.5 G36 2006
Markov Chain Monte Carlo: Stochastic Simulation for Bayesian Inference

W.R. Gilks and S. Richardson and D.J.Spiegelhalter QA274 .7 M36 1996
Markov Chain Monte Carlo in Practice

Christian P. Robert, QA279.5 R6313 2001
The Bayesian Choice

13 9 20

Tuesday, November 28th, 2006 -- By Jade

MIT的主页每天都是不同的.当然主页很多时间是一些什么生物细胞啊,计算机主板啊的, 有时主页上的画面也会特别卡通或者特别艺术. 碰到逢年过节, 也还会来点喜庆的画面. 要是中国的春节, 主页上也许会出现”恭喜发财”什么的字样. 我呢, 现在还时不时的进去看看有什么新鲜的.我还是很敬仰MIT的, MIT的主页设计也常常很有创意.

今天的主页是这样的

zip02139.gif
我看了有点不得其解. 算算日子, 11月28日啊, 这个13 9 20 是什么意思呢. 点进去看看也没说啥. 只好请教小豆同学. 小同学看了一下说: 嗨, 这不就是MIT么. “嗯, 为什么?” 我这个猪头还是很晕. “M在26个字母里排13位, I第9位 T是20位啊” 我掐指一算, 呵呵, 还真是. 好像我这两天正在看的小说:< <达芬奇秘密>> 里的字迷一样有趣儿.

突然小豆同学很腼腆的在那里说:其实, 我是很浪漫的.@#$%^. 我颇觉得莫名其妙, 这么个密码MIT有啥好浪漫的. 我大头的说:说来听听, 你又怎么浪漫了? 小豆同学又接着扭扭捏捏的说: 这个就是 “一生就爱你” 啊.

哈哈@#$%^张晓泉同学还真是浪漫加有趣呢, 难为了他还是个博士. 一个很可爱的PHD.

好奇的小家伙

Saturday, November 18th, 2006 -- By Jade

薇薇快十个月了. 她现在总是很好奇每一件事情. 经常用小手指着她新发现的东西, 脸上带着迷惑的神情, 嘴里同时还会叽叽咕咕的念道着. 有一天我在窗户上给萱萱贴了张贴画, 薇薇眼尖, 早晨一起来就看见了. 她用小手指着玻璃上的那张花, 哼哼了老半天, 知道我抱着她去摸了摸才罢. 不过时不时还会想起来去再摸摸.

薇薇看见我们用电视遥控器觉得很有趣. 这个是不可以给她啃的, 一般我们都会放好. 所以每当看见遥控器被由于我们的疏忽被放在沙发上时, 都会粉激动用她的最快的速度的连滚带爬的爬到沙发那儿, 最后在扶着沙发边儿, 颤颤微微的站起来去拿遥控器. 一次我特地没有管她, 想看看这位小姐拿着那个东西后干什么. 我认为99%的情况下, 小同学会把这玩意儿放到嘴里咬上一会儿. 可是, 小家伙却是拿着遥控器, 然后转身坐在地上, 煞有介事的对着电视, 两只小肥胳膊还往前一伸, 小手指头还在遥控器的键上按啊按的. 辛好当时电视是关着到, 否则电视非得神经不可. 有一次竟然被她按到了开关键. 然后, “啪”的一声, 电视开了. 想不到小同志, 把自己吓个哆嗦, 一脸诧异的表情. 过了2秒钟, 小人家缓过味了, 然后慢慢的转过小脸儿, 对我咧着小嘴, 乐的口水流了一下巴, 美的自己都不知道姓什么了.

所以最近给薇薇照相是个粉困难的工作. 一般情况下, 她会想尽办法去抓相机.

薇薇现在还热衷于开灯, 经常用小手指挥着抱她的人抱着她去灯的开关那里, 开灯关灯, 开开关关, 乐此不彼. 她看见灯亮了, 经常会粉兴奋的用小手指着天花板上的灯, 咧着嘴大笑.

小东西现在感兴趣的东西还有: 墙上的挂钟, 地上的拖鞋, 装了水的瓶子……….最恐怖的是薇薇对墙上的电源有着无比浓厚的兴趣, 经常称人不注意爬过去, 想去用小手指头塞到里面去.

薇薇还是很注意家里地板上的卫生的. 但凡她发现地上有一点儿垃圾纸片什么的, 不过多远也要飞快的爬过去, 然后很辛苦的用两个小手指头捡起来, 再把拿个小小的垃圾从一只手换到另一只手, 最后缓缓的放的嘴里…….所以地板是要经常擦的, 不能偷懒.

薇薇小姐最近把byebye练习的很好. 一对她说bye或者把她用小车往门外一推, 小同学就会牙牙学语的也跟着说”byebyebyebye…” 同时还会用小手摇摇的配合…

我也是把她这个小东西惯的了, 经常假哭耍赖, 撒泼打滚的, 以达到自己的不合理不卫生不安全的目的.

还有薇薇最近整个一个话痨儿, 经常自己屁股坐在自己小脚上, 身子还一颠一颠, 一扭一扭的, 嘴里哼哼唧唧的, 自言自语个没完没了. 要是听见有点节奏的音乐, 那颠的扭的就更带劲儿了, 还得加上两只小手伸在空中挥来挥去得指挥着.

我总是会很得意的对她老爸说: 看咱家的娃儿还真不傻呢. 小豆回答说: 傻?! 就她, 粘上毛儿, 比猴儿还精

就是, 薇薇还没有长牙, 唉都十个月了………..

office monitor

Friday, November 17th, 2006 -- By ET

I got the wide apple monitor, but the computer is down… one hdd failed completely.

test title3

Thursday, November 16th, 2006 -- By ET

this is a test of blogging with pics from my cell phone

Softwares on my PDA

Wednesday, November 15th, 2006 -- By ET

PocketMind PocketMusic

Burr Oak Softwrare pTravelAlarm

Skype

MobiMate WorldMate

Omega One 1-Calc

Spb Backup

PC Counselor Tweaks2k2 .NET

Resco Picture Viewer

TCPMP Pocket Media Player

Spb Pocket Plus

PocketClock 下載網址: http://www.filegone.com/xbb5

sn:7593-5495

———

Search Wireless

S/N:02873

Download Here :http://www.filegone.com/0ly1

New Download link 07/august/2006
http://www.rogepost.com/dn/i2w2/SocketCom+WiFi+Companion2.8.rar

Just Upload v2.9…using the same S/N
http://www.rogepost.com/dn/m3vm/ … panion2.9Signed.cab

汤汤水水

Monday, November 13th, 2006 -- By Jade

香港的气候湿热, 尤其夏天, 所以喝一些汤汤水水在香港是必需的. 还没到香港之前, 好友静就语重心长的对我们说要喝汤, 要饮凉茶, 否则就要长毒包, 尤其我们这些个北方长大的孩子更是如此, 云云. 听的我这个心荒啊. 虽说自己不是十七八的小姑娘了, 可是这爱美之心没有变啊. 包括我们家这位老公, 呵呵, 爱美是不分性别的.

到了这里, 真的发现汤是不能少的, 连地铁站都会有连锁店专门来卖汤和去火汤水, 凉茶. 我们自然也不敢怠慢, 里里外外, 都不会忘了煮一锅汤, 或是外出吃饭点一份例汤. 即使如此, 爱美的小豆同学脑们上还是长了3个大毒包, 历时2,3个星期. 至今, 这三个包还在他智慧的脑门上留着不深不浅的痕迹.

香港人用来煮汤的材料那可是多了去了. 蔬菜水果, 鸡鱼鸭肉, 南北干货, 中西药材, 经过不同的排列组合, 样样都可以煮汤. 不同的排列组合据说有不同的效果, 有排毒的, 有养颜的, 有润肺的,………总之听上去很美.

这些个港式汤一般煮出来都是略带甜味的. 不过这种甜味是来自食物自然的甜味, 我还是很喜欢的.

说说我最 “钟意(香港人常用单词之一)” 和常用的汤水材料吧.

1, 贵妃骨,可能是猪的肩膀的带骨头的一块肉吧. 肉质很嫩, 即使煮上两个钟头这个肉仍然很软,很香. 喝完汤后忍不住会连肉也一起吃光. 连萱萱每次都还会喊: 妈妈, 我要吃肉.
2, 蜜枣, 是那种很干的蜜枣. 我以前只吃过用蜜枣煮的粥. 到了香港才发现, 这里百分之七十的汤都要加蜜枣, 不管是鱼汤还是肉汤, 通通加上这个. 据说蜜枣润肺.
3, 南北杏仁. 至今, 我还没分出南北杏仁的区别, 只是每次煮汤时都加上一小把. 听说这个养颜解毒.
4, 红萝卜, 也就是偶们的胡萝卜. 香港人通常买很粗的胡萝卜回家煮汤.
5, 海底椰. 说实在的, 到现在我也不知道什么是海底椰,也没见过这个海底椰长什么样子. 这个东西在买的时候通常都会被切成白白的有些透明指甲盖大小的片状物. 卖东西的人说这个化痰止咳, 生津止渴.
6, 老黄瓜. 这个老黄瓜可是真老啊. 黄黄的皮, 还有点皱巴巴的. 这么古董级的老黄瓜, 我也是第一次在香港才见到. 因气候干燥引起的咳嗽, 最好喝这个老黄瓜煮的汤了, 清热解毒, 利尿消炎.

……

还有: 云耳, 佛手瓜, 鲜百合, 西洋菜, 北菇, 花胶, 章鱼干, 哈密瓜, 雪梨……..燕窝鱼翅鲍鱼什么的………数不胜数. 最简单的就是将1,2,3,4,5放在锅里咕咚咕咚煮上2,3个小时, 就会煮出一锅鲜甜的港式靓汤了.

PDA

Monday, November 13th, 2006 -- By Jade

O2 stealth

O2 Atom Exec

DOPOD 838 Pro

http://www.hkpug.org/modules/newbb/


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