I came across a senior professor in Statistics in the hall way. He noticed that I moved my office.

I told him that the new office has a window, and my research productivity increased by 5 times.

He then said:”Wonderful, they should have installed 2 windows for you.”

Hilarious!

This blog recently saw a big surge in the number of visitors from Germany. With a little tracing, I found the following website: http://www.handelsblatt.com/politik/wissenswert/studie-wie-wikipedia-markttheorien-widerlegt;2640653;0

The website is called “Handelsblatt Economy Newsletter” that reports “New trends in economics and business administration”.

It’s purely in German and the article specifically talks about the forthcoming AER paper Feng and I wrote about Wikipedia.

I used Google to translate the article, and it looks quite nice to me.

========Translated Article Below=========

LONDON. What a mistake. In the summer of 2002 reported the “Berliner Zeitung” as one of the first German media over the Internet Wikipedia – fascinated, but also skeptical: “But like the reservoir of knowledge also have large audiences and continually grow: In the near future it will not succeed, well, works of reference such as the Brockhaus outdo. “No six years later, told the Brockhaus publishing the end for the printed dictionary with – and Wikipedia now one of the most frequently visited Internet sites worldwide. Tens of thousands are working for free, voluntarily and without any fee.

A success story that brings economists provide explanations. Their traditional theories suggest that it would not even have the rise of the Internet lexicon may be. Why should rational individuals make the effort to write encyclopedia articles free of charge for an anonymous audience? Any Internet user can use the Online Encyclopedia, without himself contributes articles.

Thus, Wikipedia is what economists call a “public good” – an offer that will benefit all the people and by the use of which no one can be excluded. Classic examples of this are dikes and street lights. For public goods, so budding economists learn in basic, there is a big dilemma: There are strong incentives to freeloaders – to seize the offer without providing anything in return. The traditional economics postulates: the greater the number of potential beneficiaries, the more problems arise with free riders.

At least with Wikipedia is exactly the opposite is the case, shows a new study that appears in the upcoming “American Economic Review: The greater the number of potential readers, the more people are willing to devote their working hours for the online encyclopedia – probably because they draw mental satisfaction from the fact that their text be read by many others.

The scientists Xiaoquan Zhang (Hong Kong University of Science and Technology) and Feng Zhu (University of Southern California) have this effect after the example of the Chinese Wikipedia page. They use the fact that the government in Beijing has repeatedly censored the site due to politically unwelcome information. From October 2005, for example, were Internet users in China, the Wikipedia page does not call for nearly a year. By blocking the target audience of Wikipedia has reduced drastically over night. Million Internet users were suddenly excluded. For Chinese people in Taiwan, Hong Kong and the rest of the world, the page remained available, however.

What impact that had on the activities on the website? The researchers focused on the behavior of users outside the People’s Republic of China – people who, despite barring further access to the site and could change them. Zhang and Zhu use the fact that all changes are recorded in detail in texts on the Wikipedia page, and conceivably relate to the country in which the authors live. They compared the activities in Wikipedia immediately before and after the lock. They noted: With the start of the blockade itself have Chinese-language Internet users outside the People’s Republic of considerably less interest in Wikipedia – suddenly they wrote fewer new contributions and extended existing texts much rarer.

“The participation of authors is not blocked by the blockade decreased on average by 42.8 percent,” the economists note. The reason: The level of cooperation in Wikipedia procure satisfaction of the individual authors – researchers are referring to “social benefit”. “The shrinking group size reduces this benefit,” they write.

One indication of this is precisely the authors, where the social aspect of Wikipedia was very important and intensively romped in the discussion boards of the lexicon, wrote at the beginning of the barrier significantly less. “Our study provides empirical evidence that social effects may be stronger than the tendency to freeloaders,” the bottom line.

The study shows once again: economists make a mistake when they explain to the people to pure egoists – they can not explain many phenomena of real life properly.

An update of the system broke my almost-perfect installation of Bakoma Tex in Mac OS X 10.6 through Crossover.

It took me a few months to suffer from this tragedy. Each time when I need to work with LaTeX, I need to load my Windows 7 from bootcamp. I tried to reset the Java Virtual Machine and so on, but it could not fix the problem.

Then today I thought about the error message it gave when I tried to open CrossOver. It says “can’t load ‘/system/library/perl/extras/5.10.0…”, so it strikes me that maybe it is Perl that needs fixing.

I went to /usr/bin to list perl versions:
/usr/bin$ ls -l perl*
lrwxr-xr-x 1 root wheel 9 Aug 18 10:50 perl -> perl5.10.0
-rwxr-xr-x 1 root wheel 86000 Jun 24 2009 perl.old
-rwxr-xr-x 1 root wheel 51200 Jun 24 2009 perl5.10.0
-rwxr-xr-x 1 root wheel 34816 Jun 24 2009 perl5.8.9
-rw-rw-rw- 34 root wheel 807 Jun 24 2009 perlbug
-rwxr-xr-x 1 root wheel 38307 Jun 24 2009 perlbug5.10.0
-rwxr-xr-x 1 root wheel 45068 Jun 24 2009 perlbug5.8.9
-rw-rw-rw- 34 root wheel 807 Jun 24 2009 perlcc
-rwxr-xr-x 1 root wheel 17983 Jun 24 2009 perlcc5.8.9
-rw-rw-rw- 34 root wheel 807 Jun 24 2009 perldoc
-rwxr-xr-x 1 root wheel 255 Jun 24 2009 perldoc5.10.0
-rwxr-xr-x 1 root wheel 254 Jun 24 2009 perldoc5.8.9
-rw-rw-rw- 34 root wheel 807 Jun 24 2009 perlivp
-rwxr-xr-x 1 root wheel 12309 Jun 24 2009 perlivp5.10.0
-rwxr-xr-x 1 root wheel 12304 Jun 24 2009 perlivp5.8.9
-rw-rw-rw- 34 root wheel 807 Jun 24 2009 perlthanks
-rwxr-xr-x 1 root wheel 45068 Jun 24 2009 perlthanks5.8.9


Perl 5.10.0 is a 64 bit version. So I downgraded the perl to perl 5.8.9 by the following commands:

sudo rm perl
sudo ln -s perl5.8.9 perl


Then it worked like a charm.

I’m doing some literature review for a paper of mine. I came across the following paper:

The Business Executive: The Psychodynamics of a Social Role

By: William E. Henry

The American Journal of Sociology, Vol. 54, No. 4, Industrial Sociology (Jan., 1949), pp. 286-291.

(http://www.jstor.org/stable/2770647)

It was written in 1949, and talks about the common characteristics of successful business executives. Typically I do not find these descriptive papers useful, but it is interesting to see how people in 1949 perceive what executives should do to be successful.

The paper listed the following personality patterns that are common for success:

Achievement Desires

Mobility Drive

Idea of Authority

Ability to Organize Unstructured Situations

Decisiveness

Strong Self-Structure

Apprehension and the Fear of Failure

Activity and Aggression

Strong Reality Orientation

Different Interpersonal Relations with respect to Superiors and Subordinates

Broken Tie with his own Parents

Dependency Feelings and Concentration Upon Self

That was a long list, if you check these on people we know, say Steven Jobs, you would probably be amazed how accurate these items can “predict” his success. I’m constantly suspicious of this type of work because they obviously miss the sample of failed cases. It could be the case that people who share these traits fail more, but due to the sample selection problem, we cannot observe them. What if some other factors are driving the success of these people, and they just learned to behave in this way (i.e., behaving in this way does not produce success.)?

This brings back to the argument of my paper: when people assume social roles, they behave according to the perceived traits of these roles. In many situations, the list of characteristics is a result of being successful, not a source of it.

Here is how:


library(sandwich)
...
model1 < - lm(dev ~ ind1 + ind2)
sandwich(model1)
vcovHC(model1, type = "HC")


I’m here in Singapore for a 2-week summer institute of behavioral economics/finance. Vince Crawford, Matthew Rabin, Ted O’Donoghue and Terry Odean are the speakers.

Some keywords that surface frequently in the discussions are “bounded rationality”, “market efficiency”, “human bias”, “anomalies” etc.

This reminds me of a joke:
An economics professor and a student were strolling through the campus.
“Look,” the student cried, “there’s a $100 bill on the ground!”
“No, you are mistaken,” the professor replied. “That cannot be. If there were actually a $100 bill, someone would have picked it up.”

That is probably the most famous joke about economists. The professor is certainly a believer of Market Efficiency.

Next watch the video:

What makes all passers-by to ignore the wallet? Are lay-people suddenly believers of market efficiency?

Kindle DX dropped its price by about $100, I guess at the pressure of iPad and other ebook devices. This is good news to a lot of people who do not really want to read books on LCD/LED-based technologies. I recently lost my Kindle in a trip, so it is time to think about the next device to get to replace it.

Wei Sun recently sent me an email asking about my opinions about DX, I will put my thoughts below, as my review of DX after using it for about 6 months.

(1) How many academic papers do you read on it, and on printed form?

I put quite some papers into it, it indeed reduced my printing. But journals like MgtSci, MktSci, ISR have too small fonts (kindle’s font is slightly smaller than the real journals), so in the end, it is still not too comfortable to read on DX. Once you rotate it to read in landscape mode, the fonts are larger (larger than the real journals), but you need to do a lot of page-ups and -downs to read them. If the new version can improve the speed of page flipping, it will be better, otherwise, it is a headache to read journal papers. AER and JPE are fine because they have large margins and kindle can crop them automatically.

(2) Do you find it helpful for academic research?

Yes. I mostly read ebooks on it. It is best for ebooks and I love it. For PDF versions of ebooks, I can use a software called calibre to convert to ebook format so I can change the font on the device. DX has 3GB, I put hundreds of books into it, there’s plenty of space.

(3) In your opinion, are there any better alternatives? How about Apple ipad?

ipad is not based on E-ink technology, so it does not make a big difference from reading on a laptop screen. The biggest reason for me to buy kindle is that it feels like reading from paper on kindle, and it’s good to the eyes. For reading papers, I would not use ipad. An alternative to kindle is a device called QUE, you can google for it. I learned about it after I bought my kindle last december, but it then pushed off the release date, the most recent news was that it announced it would release on June 25. I don’t think many people have evaluated it now, but this half year delay for sure put a big damage on the product. For one, ipad is out, many people simply get ipad, second, kindle dx has dropped price, QUE’s price at $500 is too high now. But a nice thing is it has the largest possible E-ink screen on the market. The monitor is similar to normal letter-sized paper, so it will be like exactly reading a printed paper.

(4) Overall, do you recommend it at $400 as a research tool?

Bottomline: I would say if you read a lot of books like I do now (I did not have time to read books when I was a student), it will be really useful. Otherwise, hold for a little while to see how QUE performs.

(本文所有照片都可以点击看大图)

标题是春天的巴黎的意思。好久没有写中文的东西了，上次还是两年前写南京的游记，今天写写巴黎之行。

小豆诧异了半天，说我变风格了。

这次是受邀于巴黎第十大学(Universite de Paris X) 和 Universite de Rennes I参加一个workshop。本来假期时间很紧，不想去的，不过和Erik的东西需要有个契机推动一下，另外对方报销所有费用，所以就勉为其难的去了，呵呵。

巴黎大学也叫 Sorbonne, 我住的附近路名都叫 Rue de la Sorbonne。这里也是著名的拉丁区，以前做学术的都要讲拉丁文，所以这个地方就叫Latin Quarter。国内经常看到左岸这，左岸那的，就是指的这个区域，因在塞纳河的左岸而得名，是小资一派的麦加圣地。

附近著名的景点就是卢森堡公园 (Jardin du Luxembourg)：里面以诸多文艺愤青的雕像而著名，我看到了乔治桑（George Sand）, 肖邦和她同居10年之久，并曾经为她谱过曲。

Workshop两天，日程及其紧，比较失望的是第一天不少talk都很preliminary，没有什么意思，好在第二天有些不错的paper。另外见到了一直想交流一下的几个人，所以时间不能算浪费啦。 巴黎偶来过3次了，这次是第一次做学术交流而来，很久之前给公司做路演，参加展会，去年来参加wedding，所以身份从白领，到游客，再到学者，每次的体会也会不同。

中午的午餐很别致，我吃得不多，和与会者聊天更有意思一些。

Paul Belleflamme给我的印象很深，以前做Piracy和Pricing of Music研究的时候读过他的文章，最近他出了一本IO的书

有机会会买一本读一下。

我的那个session叫做 Socially Optimal Incentives，看了一下，至少还可以在另外两个session讲我另外的paper，分别是 Online Advertising 和 User Generated Content （UGC）。

Workshop结束的时候正好赶上法国的Gay parade，看到不少有趣的人。

队伍里有帅哥美女，也有大爷和小朋友。那个白胡子大爷举的旗子是法国西北部著名的Brittany的旗子，去年参加Grace和Benoit的婚礼曾经去过。

这些人都很友善，而且游行时都很proud，偶很受感染。（不是说取向方面，而是positive面对人生方面）。

第一天会议结束后随便走了走，照了些像，都是去过的地方，所以玩了些艺术手法：

晚上和组织会议的Eric和Thierry吃饭，竟然用了4个小时，8点一直到12点多。完了顺道去拍了几张夜景照片。

第二天下午有一点点时间，就在傍晚前拍了些日落前后的照片，效果更佳。

我自己最喜欢的是这下面的巴黎圣母院的照片：

开完会后的周日，我很想去巴黎附近的小城看看，其实有不少选择的，可以去枫丹白露Fontainebleu（直译是蓝喷泉的意思），或者一个叫Provins的地方看中世纪的古堡和教堂，或者去重游Brittany，去上次没有去过的Mont Saint-Michel, 也可以去Loire谷看城堡，不过这几个地方小豆也都没有去过，而且有些地方开车去比较方便，所以可以留着下次一起去。最后决定了去一个叫Chartre的地方，离巴黎有80公里远，此地有名气仅次于巴黎圣母院的一个教堂(Cathédrale Notre-Dame de Chartres)。火车站就在离我不远的Montpanasse，走路就可以到了。卖票的黑人大叔态度不怎么样，所以我费了半天劲才figure out怎么找火车的站台，多亏当年学过一年法语的底子，连猜带问人，总算上了车。一个小时后火车开到一个叫Maintenon的地方，我还在车上美呢，列车员过来告诉我这个车马上就原路返回巴黎了，下面要换坐大巴了。我还是很牛的，这些法语都听懂啦。

大巴开了20分钟远远就看到那个教堂了，下了车是火车站(Gare Chartre):

小城很不错，教堂也很壮观，当天还有礼拜，正好赶上了

周一去巴黎大学访问，顺便去了旁边的L’Ecole Normale Superieur 是居里夫人等牛人工作过的地方，出过12个诺贝尔奖和9个菲尔兹奖的得主。

当然在巴黎还有必做的两件事：美食和购物。

我每次去都不会错过的就是 鹅肝酱（foie gras），牛排（entrecote），生蚝和海鲜盘（fruits de mer）和比利时的Moules。在我附近有一家我仰慕已久的餐馆叫 Les Papilles，刚到的那天就去采了点，准备周日去，结果他们很拽，周日休息。 等到周一去，waiter告诉我又不营业，只有等到周二中午才在走前匆匆去试一下。结果吃到了我此生最好吃的午餐。本来没有太多期望的，所以就点了不起眼的”marmite du marché”, 就是个午餐套餐。上来的鸭胸肉火候几乎perfect, 撒些旁边的颗粒状海盐吃，简直让我惊艳万分。比起前几日在比其贵很多的餐厅里吃过的鸭胸肉还好，水准直追米其林3星的水平。

购物方面就是四处转转了，看到LV门口永远排着一串中国，韩国和日本的女士们。去老佛爷的酒窖看看，一个华人sales围着我让我买Chateau Lafite， 当我是国内暴发户啊。最后买了性价比极高的 Chateau Canon 05 和 Chateau Magdaleine 03。

Before tweaking MySQL: it used 5% of the CPU and 250MB of the memory.

After tweaking, it uses 94.3% of the CPU and 2.33GB of the memory.

I could increase the memory use even more if I needed it.