Dave Rosenberg, chief economist at Gluskin Sheff, said there was no real breakthrough in the bond market, and that current interest rate yields did not significantly break the mean and median levels since 2009. Interest rate 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. 1. The amount of the shares, the capital of the company is divided into shares, and the amount of each share is the same, that is, the shares are a reflection of certain value and can be measured in currency; In 1937, American economist Robert coase (R. H. Coase's publication of the essence of the enterprise is considered to be the beginning of a discussion on this issue. In the week ended Dec. 15, U.S. crude stocks fell 520 barrels to 438.7 million barrels, the API said, with analysts predicting a decrease of 3518,000 barrels. Cushing's crude inventories rose by 70,000 barrels.