From an economic perspective, there are two basic problems: the first is the issue of incentives and the second is the issue of coordination. In the final analysis, the system is used to solve these two problems. No matter what method you use, as long as it can be solved, it is a good system. Therefore, there is no standard system in the world. When people get rid of these basic problems and simply apply certain concepts, they fail. What does this text mean? ['Importance of solving incentives and coordination.', 'How to use economic principles to evaluate a system.', 'How to use economic principles to solve practical problems.', 'Establish the fundamental purpose and evaluation criteria of the system.']