爱华网北外校园内有两个卖旧书的老伯，每天带一大筐书到食堂附近卖。原价60元以上的书他一般卖10元-20元。
由于北外只有这两家旧书摊长期营业，而他们经营的书籍一般是不一样的，于是他们构成了小范围的寡头垄断。这过程中首先涉及了供给与需求的原理。北外是外文书籍需求十分大的地方，而供给主要是外研书店，清源书店和新图书店。而这三家中外研书店的外文书比较齐全但是价格是100%没有折扣的。在这里学生们就有了“选择（choice）”，究其原因，选择是由稀缺资源引起的，而在这里，原版的外文书籍就是稀缺资源。而学生是属于几乎没有获取收入能力的，于是选择在外研书店买书的比较少。清源和新图书店主要营业教辅学习参考书。话说回来，从机会成本的角度来看，因为旧书与新书大部分相差不大，基本不会影响到学生的书籍阅读（即书的效用是几乎一样的），学生在旧书摊买书的机会成本相对较小，于是学生们是会选择到旧书摊买书的。从消费者剩余的角度看，消费者（学生）的心里对这本书的预期价格是比原价低的一个价位以下（打个比方，原价60 的书卖30以下他就可以接受），于是在10元一本的情况下，他仍然有20元的消费者剩余。从生产者剩余的角度看，根据调查，每本旧书收购价大概在1-4元左右，他能以10-20元卖出，生产者剩余显然是很大的。这样以来，社会的总剩余是增加的，也就是社会总福利是增加的，社会将便的更好。
但是由于旧书摊是无执照经营，影响了学校的合法书市的生意，于是就有新的rule，即学校规定旧书摊不准摆进北外校园，并由保安进行督促管理。这又涉及到了新制度经济学的知识。新的rule打破了旧的体制和制度，引起了新的问题。
在新的制度下理性的人们会有新的对策，这两位老伯也不例外，虽然一看就知道他们没有学过经济学理论。
其中Customer loyalty是一个很有趣的问题，一位老伯将卖书的地点转移到了北外东西院之间的地下通道中，老伯在平时经营时认识了一部分学生，于是这部分学生还经常去地下通道光顾。这样老伯便拥有了一部分
Analysis of an economic case
The case of the second book market in BFSU
There are two old men selling second hand original English version books. Everyday they would bring a case of books for sale near BFSU’s dining hall. They charge 10-20yuan for a book with the price of more than 60yuan.
As BFSU has only two second hand book markets, and the books they are selling are basically different, so they form a small area oligopoly. In this course, firstly, it refers to the principle of supply and demand. The demand for foreign language books is quite high, and the main suppliers are the bookshop of Foreign Language Teaching and Research press, Qingyuan bookshop and the bookshop of the new library. However in these three bookshops, the bookshop of Foreign Language Teaching and Research press offers the largest range of original version foreign language books, yet it gives no discount. Here students have got choices, and the “choices” are due to the scarcity of resources(here the resources are books) And as is widely known, students are mostly unable to make money, so the bookshop of Foreign Language Teaching and Research press has less appeal to the no-income students. What’s more, Qingyuan and The bookshop of new library are both in the business area of reference books of English study. So take all things into consideration, especially in the light of the opportunity cost, the quality of old books and new books are literally more or less the same. Most second hand books will not affect people’s reading. (i.e. the utility of the books are almost the same) , so it is a wise choice to choose second hand books. And in the aspect of consumer’s surplus, the consumers expect one book to be lower than, say, 30 Yuan (half the full price), so if he buys the book for 10yuan, he gets extra 20yuan as the so called consumer’s surplus. And in the aspect of the producer’s surplus, in accordance with my research, each book is bought for 1-4yuan, and the old men could sell them at 10-20yuan, evidently the margin is quite big. In this way, the total social surplus is positive, and social conditions will surely be better. This is also the principle of “exchange can improve the well being of both parties”.
But as no the two old men hold no legal licenses to take part in the business of selling the books, and their behavior does affected the business of the law-and-order businesses, there occurs a new rule. i.e. the school regulates that no second hand book markets could exist in BFSU, and actions are taken to ensure the rule. Obviously it again refers to the realm of “ ”. the new rules break out of the old system and created new issues.
Under the new system, rational people will make rational strategies; there is no exception to the two old men, although we could bet they haven’t got any academic education of economics at the first glance.
And customer loyalty is an interesting issue to pay attention to. Under the new circumstance, one of the
常客，他们会时不时地光顾或是介绍新的顾客给老伯，这就是所谓的customer loyalty. 另一位老伯从那时起便开始了电话联系，他把以前的认识的customers的电话记下来，时常联系联系，也能接到一些业务，而他的书摊主阵地转移到了别的一个学校。
在一年的观察总结下，我还得出了几个
重要的结论。第一个是消费者的偏好对消费的影响。第二个是定价对交易的影响。书籍的消费者一般喜欢文艺类的，传记文学英文作品并且是比较有名畅销的书。据观察，一位老伯的书总是卖的比另一位的好，原因就在于他卖的旧书总是一些畅销书，比如 “a
memoir of a geisha” 等。而另一位老伯一般卖惊悚小说（thrillers），但总是卖的不好。这就是消费者的偏好对消费的影响。
关于定价，这与书的弹性有关。
这个案例也体现了二级价格歧视。一般买一本书可能需要15元，要是买两本，一般可以10元买到。
Old man transfers his location to the underground passage between east campus and west campus of BFSU. The old man makes acquaintance with some students of BFSU. So these students still take the trouble to go into the passage to have some business with him or introduce new customers to him. This is the so called customer loyalty. The other old man started liaising his previous customers with the assistance of phones. In fact he has already jotted down his customers’ phone numbers, in this way, he can also be rewarded some businesses. And as a matter of fact his location has also been transferred to another place, another school.
With a year’s observation, I have drawn several other conclusions. The first one is the crucial importance the “taste” plays in determine consumers’ choice-making. The second is the impact of price setting. Foreign language fanciers often favor literary masterpieces, autobiographies or biographies, always with the title like “New York Times No.1 best seller”. As I have long observed, one of the old men’s books always sell faster than the other, looking into it, I found the second hand book he possesses are always best sellers, such as a memoir of a geisha. However, the other old man sells thrillers mostly. It explains everything if you compare the two. And this is the crucial importance the taste plays in determine consumers’ choice-making.
As to the price-setting, it’s relation with the elasticity of demand of books is undeniable.
And second level price discrimination is apparently shown in this case. One book may cost you 15yuan, yet you can purchase 2 by 10yuan each.
