1. opportunity cost-the value of other things you give up to do this. 2. cost-effectiveness principle-you should do this only when the extra benefits brought by the action are greater than the extra costs. 3. principle of "no free lunch"-if a company provides "free" extra services and tries to include this cost in the basic product price, then, Competitive buyers can attract buyers who don't want to use additional services by reducing the price of basic products and charging for additional services separately. 4. The designed functions should conform to the principle of cost-effectiveness: if and only if the income (measured by the number of consumers willing to pay additional fees) is not lower than the cost (measured by increasing the number of consumers attracted by a certain function), a certain product function should be set up. 5. In the long run, the cost saved by new technologies, It will not bring higher profits to producers, but reduce the price of products and benefit consumers. 6. "law of one price" pointed out that any supplier who tries to take advantage of the idea that the rich are willing to spend more money will create direct profit opportunities for competitors.

7. Market clearing price: When the number of consumers who are willing to buy the product at the mainstream market price is equal to the number of producers who are willing to sell the product, the market for a specific product is in equilibrium, that is, the demand is equal to the supply. 8. Basic principles of competitive labor market: the wages of employees are roughly proportional to the value they create for their employers above the breakeven point. 9. law of one price is most suitable for a completely competitive market. However, in the actual product (especially expensive products) market, the possibility of arbitrage limits the monopolist's ability to charge high prices from special buyers 10. Discount threshold: the seller allows customers to buy at a discount price, but only if the customers first jump over a certain threshold1/Adam? Smith's invisible hand is based on the following implicit premise: the individual's return depends only on absolute performance. But in fact, most things in life are determined by their relative positions. 12. "Principle of Difficult to Fake": If a signal between potential rivals is true and reliable, it must be difficult to fake (or it is too expensive to fake).

13. There are two kinds of buyers in the market, one is people who don't know what they are doing, and the other is people who don't know what they are doing. The first kind of buyers, because of their lack of knowledge, don't understand what the visible connection between price and quality implies, and sometimes can limit their losses 14. Per capita income is the most significant difference among countries. Most people with different incomes will make different choices, regardless of their cultural background. 15. Sources of international differences: the opportunity cost difference caused by different occupations, the different economic policies of different countries, and the different motivations brought by different social customs. 16. Behavioral economics tells us that if we want to understand the choices people actually make in economic activities, we must make a more detailed analysis of human motives./kloc-. But people tend to prefer other forms of rewards 18. Women who are relatively attractive in appearance are mostly accompanied by relatively smart men. If beauty and wisdom can be inherited, then the offspring of this combination are often higher than the average in both aspects 19. Frustrated talent, hidden cost: Will film special effects drive the most talented martial arts instructor out of the market?

The Economics of Milk Coke is a book published by Renmin University of China Press in 2008. The author is robert frank Robert H Frank, a professor at Cornell University School of Management in the United States. He likes to give students "homework on natural history economics" in his class, so that students can write short essays, ask questions in life and answer them from the perspective of economics. After several years of accumulation, these problems have been collected into a book, and the author has extracted more than 100 cases from them to edit the cost book, teaching readers to look at life and work from an economic perspective, and skillfully applying economic principles in different environments, and at the same time, experiencing the beauty of being an "economist". Reference1.http://ww w.jianshu.com/p/4b75e9b60a2e