how to calculate the net profit margin First of all, it costs transaction cost for the manufacturer to purchase intermediate products in the market. It includes the cost of seeking suitable suppliers, signing contracts and supervising contract execution. If the manufacturer can produce some intermediate products within the enterprise itself, it can eliminate or reduce some transaction costs, and can better guarantee the quality of the products. Second, if the manufacturers need is a special type of specialized equipment, the supplier does not generally willing to specialize in only a buyer of the product of the investment and production, because this kind of proprietary investment risk is bigger. Therefore, vendors that need this specialized device need to solve the problem of specialized devices within the enterprise. In the end, the manufacturers hire employees with specialized skills, such as specialized product design, cost management, and quality control, and establish long-term contractual relationships with them. This can be more beneficial than buying the corresponding services from other vendors, thereby eliminating or reducing the corresponding transaction costs. Modern economy, the interest rate as the price of money, not only restricted by many factors in the economic and social, and changes in interest rates to have a great impact on the economy as a whole, as a result, modern economists are studying the interest rate decision problem, pay special attention to the relationship between the variables and the balance of the economy as a whole, the interest rate decision theory has experienced the classical interest rate theory, Keynes's interest theory, interest rate in loanable funds theory and is-lm analysis as well as the contemporary evolution of dynamic interest rate model, the development process. Suppose a speculator decides to enter the foreign exchange futures market. He is going to take out $10,000 to speculate. He selected the broker bank and registered representative, opened an account, and deposited the money. To be on the safe side, he decided to do sterling business first and then gain some experience before entering other markets. In the face of market failure, coase has given the opposite answer: external-utility problems can be solved by explicitly using the market, without government intervention. And zhang wuchang is more absolute, he said that there is no so-called external utility, there is only unclear property rights. Anyway, coase brought revolutionary innovation to market concepts. He made it clear that the key to the market was not the "price mechanism" of impersonal machinery, but the power of participants in economic activity. 1. Enterprise income tax Yes, the application's error, yes, you're overcharging. It is now decided to return two tickets with two railway CARDS. There is no sign of apology in the response, which is just a "gesture of goodwill", which adds two standard return tickets to your chosen journey. When Bob Corker, the conservative republican chairman of the senate foreign relations committee, publicly warned that Mr Trump might launch a third world war, you should worry that it was time. If you don't believe it, consider the recent history of Russia or Turkey. Or the history of the Romanempire under Caligula or Nero. For centuries, Pluto's populism has turned democracy into an authoritarian state. There is no reason to think they will stop now. The rule of the trump emperor may be coming.