Investment in securities provides an important channel for the society to raise funds, which is an effective way for enterprises to raise direct financing. Read more Mr Trump and the republicans' plan to repeal the 2010 "affordable care act" will bring 24 million americans - most of them poor or middle class, many of whom vote for him - without health care. His deregulation policy was a blatant bigotry of workers and unions. And the republican tax reform plan he endorses will overwhelmingly support multinational corporations and the top 1 percent of families, many of whom are particularly benefiting from the repeal of the estate tax. 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. As we work hard to earn a fantastic living and pay our charges, additionally, there are crooks who generate a living by robbing from unsuspecting victims. Thus, we should instead always be on guard from such individuals by securing our personal data and making sure that they may not be extracted from us and employed for crooks' advantages 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. In the early 20th century, famous American economist elvin fisher developed the theory of economic gain. In its book "the nature of capital and yield", first, the concept of yield is analyzed in terms of the performance of earnings, and three different types of benefits are proposed: