Tag Archives: University of Pennsylvania

Social learning and dynamic pricing

Ohhhhhhh, this week I was too busy to listen to the seminars. Fortunately, on Thursday I finally got a little time to audit a speech by a Chinese guy from Upenn. Haha~ It is not common to see any other Chinese here.

However, I came there because of the topic, not his name or something else. I was attracted by his title at the first glance, since I really would like to know something about social learning. That's a pretty interesting issue to talk, and requires enough mathematical skills. So....the related information first, as usual:

Dynamic Pricing in the Presence of Social Learning
Xi Weng (University of Pennsylvania)

UPF Internal Micro and Behavioral Economics Seminar

and here is the abstract attached:

This paper considers a monopolist selling a new experience good over time to many buyers.
Buyers learn from their own private experiences (individual learning) as well as by observing other buyers' experiences (social learning). Individual learning generates ex post heterogeneity, which affects the buyers' purchasing decisions and the firm's pricing strategy. When learning is through good news signals, the incentive to exploit the known buyers for the monopolist causes experimentation to be terminated too early. After the arrival of a good news signal, the price could instantaneously go down in order induce the remaining unknown buyer to experiment. When learning is through bad news signals, experimentation is effcient, since only the homogeneous unknown buyers purchase the experience good.

Enough background. I am interested in social learning because it considers a dynamic process of the production delivering process. Such as Ipod and some other fashion products sold in the market, there must be some "loyal" fans who would like to try and share their experience firstly, and then more and more potential consumers will do the purchase in turn.

Eh.... Nothing more to say? Maybe there are too many math formulas which makes me confused......Anyway, good luck, Xi!

Stochastic calculus [4th week, Sep]

Today when I was checking my emails, I noticed one ad from The Wharton School of the University of Pennsylvania. There was no doubt that it is the most famous business school throughout the world.  But in fact, at the first glance, I didn’t realize that it is Wharton. I just thought that “oh, a school of Upeen“.

Followed its link, I was redirected to its official website, and read the introduction of its applied economics doctoral program. Although I did know that upeen would never give me an admission, I still looked carefully at the details of the program’s requirements. Of course, I paid much attention on the mathematical requirements. Some familiar words came into view, like

(1) at least two courses in calculus, (2) linear algebra, (3) differential equations, and (4) probability and statistics. We also recommended that you have taken: (1) real analysis, (2) econometrics, (3) stochastic calculus.

Ok… I have one year left to meet your requirements. However, the fact is, even if I can satisfy all the basic requirements of this program, I am still not competitive enough and I have no money to pay for the tuition. Thus, the final result mentains the same: It has nothing to do with me. Moreover, I would prefer the training of theoretical economics rather than applied economics.

Here I want to say something about “stochastic”. Some days ago one junior attracted my interest, not for his intelligence, but for his love of mathematics as a student of economics. I had met hundreds of schoolmates who had a good knowledge of math, either took some classes from the school of mathematics or taught themselves. But most of them were forced to enhance their math ability by the pressure from graduate schools or their advisors. Therefore, the real situation was, they did have some calculation skills after professional math trainings, but seldom did they really have the understanding of the spirit of math.

That boy was different. He didn’t got high marks in every class, thereby losing the most valuable testimony of outstanding performance at study. “The only choice for me is to take part in the entrance exams for postgraduate schools ( which is called ‘Kao Yan’) since my lack of English and GPA “, he laughed at himself when I encouraged him to go abroad. But he told me that he had audited most of the core courses in school of math. That day we talked about a question about matrix, or more specifically, Markov chain. He offered a new solution way, which was really out of my thought. I didn’t catch his meaning at first, so he explained it patiently. After that, he recommended me to listen to the course of stochastic process in school of math. To speak honestly, I had some knowledge about stochastic process so I told him. At first he was a little surprised, but soon he gave me an advice for the reason that my understanding of stochastic was not deep enough. Then he gave me a list of the courses and asked whether I would come to the class or not. Unfortunately, the time was conflicted with an other class on Tuesday afternoon. He said that it didn’t matter, since I would go to another half  of the course on Thursday and the course was pretty easy. OK, I will certainly do that.

Of course, as an exchange, I provided some suggestion for the economic courses…

Now what I want to say is, why “stochastic” is so important in economics? It seems that every one has an unique answer, so do I. But today the word “stochastic calculus” really makes me confused. After searching on the Internet, I have a basic conception of it. But why it sounds so familiar? …

Yes, Shige Peng （彭实戈）! And his backward stochastic differential equations! I see… I see…

Appendix:

Some Chinese materials about Stochastic calculus ( Author unknown, sorry! ).

Continue reading in Chinese »