how to improve gross profit margin The essence of economic value is human labor in the process of human economic products and relations. The value of the use value of creating products and the labor value of creating production relationship. The value concept in "das kapital" refers to exchange value, which is the essence of capital relations. Can't be replaced by local value Although an enterprise's internal trade fair eliminates or reduces some of the market transaction costs, it also brings with it the specific transaction costs of the enterprise. The main reason for this defect is also the incompleteness of information. Specifically, first, there are various contractual relationships among enterprises, including contractual relationship between enterprises and workers, contractual relationship between enterprises and managers, etc. The enterprise should supervise the work of the workers and products that it employs, as well as the managers and other personnel, and induces them to work hard for the enterprise. So, companies are signing contracts and spending on oversight and incentives. Secondly, on the one hand, corporate decision makers often need to obtain information from subordinates. On the other hand, the decision-making information of the upper level of the enterprise should be realized by passing it to the subordinate. The information transmission of these two different directions will be distorted by the increase of subordination of enterprise scale, resulting in the loss of enterprise efficiency. Once again, the subordinate of the enterprise often conceals or passes the wrong information to the superior for selfish motives, so that the superior can make decisions that benefit the subordinate. Or, the subordinate's decision to the superior only passes or executes the part that is advantageous to oneself. These will result in the loss of enterprise efficiency. Thus, the expansion of enterprises is limited. According to coase's theory, the scale of the enterprise should be expanded to this point, that is at this point to increase the cost of an internal exchange cost equals the cost through the market exchange cost and so on. When bank of America merrill lynch survey of investors results also showed that as many as 8% of the respondents expected net amount, 2018 of the yield curve will become flat, it is up to the number of records since June last year. Bed Prism Glasses or Lazy Glasses, because they are often called, are an aid to relaxation. They are used mainly take it easy during sex reading a book or viewing television or sometimes by patients during recuperation from illness or injury, where long-term bed rest is needed. Certainly not for anything that could be termed as a Sports Activity, besides watching the football on TV, during sex, perhaps! The investment of securities provides an important means for the central bank to conduct financial macro-control, which is of great significance to the sustainable and efficient development of the national economy. Gasoline sales in the United States are mainly due to competitive gasoline prices and rising fuel efficiency, with a high seasonal impact. Population and cultural factors are also important factors that influence the trend of gasoline consumption in the United States, according to Jill Mislinski, an analyst with Advisor Perspectives.