The macroeconomic impact of many factors is running itself is a complex socio-economic system, the study of economic fluctuations need complex science and system science theory perspective. Based on the theory of system science, the growth and volatility of the national economy is a special and complex socioeconomic system. The theory and method of using the system science are the new perspective and ideas of the law of economic fluctuation.

First, the characteristics of economic system and complexity analysis

In 1947 and 1955, L. von Bertalanffy published "General Systems Theory" and "General System Theory", 1957, H.Good and REMaeh01 published the "System Engineering ", the system of science and systems engineering theory has been greatly enriched and developed. System theory, cybernetics and information theory constitute the basic framework of systems engineering science. The theory of synergetics, catastrophe theory and dissipative structure theory is the new achievement of systematic scientific research. Complexity research is the new progress of modern system science research.

Understanding the basic types and basic characteristics of the system is the starting point of the system analysis. There are physical system, social system, cosmic system and so on; there are engineering system, social system and ecological system division. There are physical system, social system and cosmic system. Qian Xuesen proposed class concept class classification from the perspective of system complexity, which is regarded as a typical and complete system science classification. The above system classification method reveals the diversity and complexity of the system, but the relationship between these categories is not very clear. If you know the system from the basic characteristics or basic laws of the movement of the system elements, you can understand the relationship between the various systems in a more simple and clear way.

(I) the division of economic systems

From the perspective of system science to understand the objective world, the objective world is composed of different systems. Based on the conceptual system classification proposed by the complexity of the system, and the classification of the conceptual system and the entity system, it can be seen that the economic system is the most important part of the social system. Basic component. As shown in Figure 1.

Whether the system exists as a standard for human activities, the objective world can be divided into two systems. One is the existence of human activities do not constitute the system that the physical system; one is the existence of human activities in the social system. These two types of systems can be used as the most basic system. Physical system and social system of the law of movement there are significant differences, and the stability of the system movement law is the physical system and social system, the main difference between the two systems.

The physical properties of the elements in the physical system are determined, and the law of motion is stable. The system must follow certain laws. Physical system is regular and can be repeated test, people can make a more accurate system of movement to predict and be controlled. And the social system as the basic elements of the property is unstable, especially between people there are significant differences between the social system movement is also expressed as uncertain. Thus, the trial of the economic system can not be repeated, which is a fundamental reason for the special complexity of the economic system.

The economic system is an organic whole that focuses on human activities, involving social, economic, science and technology, culture and education, ecological environment and other fields. The fundamental difference between the economic system and the physical system is that there is a decision-making link in the economic system. The behavior of the system is always carried out after the information is collected and made according to a certain policy of information processing. Therefore, the subjective will and preferences of the system have a greater impact. Economic system is the most basic part of the social system, natural science research methods are more applied to the economic system research, making the economic system of the law of movement has made great progress. However, compared with the natural sciences, the economic theory of economic system movement is not accurate description of the law, many concepts and definitions of ambiguity and the prevalence of many different academic schools is a good proof. This is determined by the particular complexity of the economic system. (B) the characteristics of the economic system

1 Economic system of non-determinism, ambiguity, uncertainty. The main elements of the economic system are people, all the activities of people and the relationship between people and the environment. Where someone involved in the activities are a certain purpose. The economic system involves many aspects of human life and many factors of the surrounding environment. Because of human thinking, judgment, decision-making and preference, there are obvious non-deterministic, ambiguity, uncertainty and so on. Characteristics, resulting in the analysis of the social and economic giant system difficulties. Therefore, the development of economic system by the subjective will and decision-making links of the great impact.

2 The economic system is a typical unbalanced open system. The national economy itself is a non-equilibrium system: from a spatial point of view, industry and industry, between departments and departments, between regions and regions and between enterprises and enterprises between the economic development, has always been uneven; Time series, the speed of economic development is nonuniform, there are regular economic fluctuations and meta-rules of random disturbance superposition, resulting in the process of economic development fluctuations in the phenomenon. The imbalance in the economic system is frequent and universal.

3 economic system is a multi-objective, multivariable, non-linear complex. Multi-objective, multivariable and non-linearity determines the relationship between the economic system and the complex interdependence and mutual restraint. It is difficult to coordinate with each other by empirical and qualitative analysis. Therefore, how to make the multi-variable and non-linear relationship is the best of the economic system to solve the key issues.

4 economic system by the natural environment and social conditions of the dual constraints. Economic system is in a certain natural environment and social conditions (social system, economic system) formed, it must be subject to the natural environment and social conditions of the dual constraints. It is pointless to take away the double economic system to examine any level of economic system.

5 economic system with multi-level, multi-form and versatility. Recognize and discover the inherent feedback system mechanism formed by the causal relationship in the macroeconomic system is the so-called law of economic development. However, the fundamental difference between the economic system and the physical system is that there is a decision-making link in the economic system. The behavior of the system is always after the information is collected and the information processing is made according to a certain policy. Therefore, the economic system is composed of non-life and life system of the overall dynamic system, the system has the basic characteristics of self-discipline and non-linear. The so-called self-discipline is their own decision-making, their own management, control, constraints of their own ability and characteristics. In the "cybernetics", Wiener stated that from the organism to the engineering system and the economic system, they have a common structure in which there is a feedback control mechanism.

(Iii) the special complexity of the economic system

The social attributes of the social system as a basic element is unstable, especially between people there is a significant difference between the social system movement is also expressed as uncertain. Thus, the trial of the economic system can not be repeated, which is a fundamental reason for the special complexity of the economic system.

There are different definitions and understanding of the complexity of the problem, different angles, different subject background, different research objects. Massachusetts Institute of Technology's seth LIovd lists at least 31 definitions of complexity. Diversity, uncertainty is the inherent connotation of complexity, such as: complexity is a dynamic behavior of the system, often accompanied by fluctuations, is dynamic, open, away from the balance; is the system, the organization's intrinsic attributes rather than Individual, unit-specific attributes, self-organization and adaptability from non-linear interactions between the various parts of the system, especially in economic systems.

The causes of complexity are mainly due to the multivariable characteristics of the system, the non-linearity, the inhomogeneity of the space-time structure, the heterogeneity of the system and the openness of the system. Complexity makes it easy for people to obtain complete information of the system, so that the lack of adequate understanding of the movement of the system, it is difficult to accurately describe and explain.

The complexity of the economic system is manifested in the actual economic activity. On the one hand, the relationship between all the elements of economic activity is complex and the economic operation is often manifested as randomness and uncertainty. On the other hand, the economic problem is the social The real problems and phenomena of economic activities are often manifested as non-linear, irreversible evolution, away from equilibrium, such as irregular fluctuations in macroeconomic activity, fluctuations and so on. In the social and economic system due to the initiative of human activities, so that the economic system shows a special complexity, the special complexity of the economic system determines the economic theory of economic system movement laws have a greater limitation. From the perspective of scientific research methodology, Western mainstream economics from Adam. Smith has evolved over the past 200 years. After several revolutions, it is still used to study the complex economic activities and complex economic phenomena with a single causal relationship, such as equilibrium, rationality, stability and optimization. , Argumentation, interpretation and prediction, that economic relations, economic activity is linear, without interruption, chaos and mutations in the world. Therefore, mainstream economics is to some extent Newton's classic scientific thought in the application of economics, are in the Newtonian mechanics as the representative of the deterministic analysis of the framework of the economic phenomenon of the study.

The dissipative structure theory proves that the economic system is a dissipative structure and follows the negative entropy law. The new research perspective and ideas make people realize that the economic system is an evolving, complex nonlinear system, the economic phenomenon is no longer a reflection of market stability and balance of supply and demand, but the interaction of many individuals in the unstable situation Continue to adjust the relationship between the results. Economic system is inherently unpredictable, its behavior and the result is no longer a single and linear, but coupled with the non-linear effect of each other, the economic system will therefore lead to instability, uneven operation and uncertainty Of the fluctuation.

Therefore, the researcher must apply the theory of systematic science, apply the complexity of scientific theory and instability, uncertainty, diversity, study the complex economic system and its complex operation, explore research, analysis, demonstration and interpretation Economic System Evolution and Handling Uncertainty of Economic System.

Second, the economic fluctuations of the multi-factor analysis

Previous studies on the causes of economic volatility have shown that there are many reasons for economic fluctuations, and the relationship between the various causes is complex. From the various factors and categories that cause economic fluctuations listed in Table 1, other factors are related to people's production activities, except for natural factors. Human economic activities are the complex and diverse production, exchange, distribution and consumption activities affected by many factors under different social and historical conditions, under certain social factors, under various social systems. In a variety of factors, Under the influence of economic activity will inevitably fluctuate; coupled with the random behavior of human behavior and natural impact of the sudden, economic fluctuations also showed an unexpected impact.

Table 1 shows that there are many factors that may cause economic fluctuations, and because of the special complexity of the economic system, economic fluctuations are bound to show a high degree of complexity. Studies have shown that every economic fluctuation that has occurred in history has been different, and people have not yet found a specific period of economic volatility or a specific causal relationship that causes volatility.

Economic fluctuations show the main reason for the complexity of the main reasons can be attributed to several aspects: First, the economic fluctuations of the multi-cause. Table 1 shows that economic fluctuations are not only a lot of factors, but also interrelated, can not determine which factors are the most important. Existing research can be seen that there are many factors that cause economic fluctuations, such as natural factors, external shocks, internal fluctuations, political factors, economic factors and so on. Second, the economic variables quantify the ambiguity. The measure of economic system variables has a great deal of subjectivity, and the acquisition and dissemination of information also has a strong subjectivity, which determines that the measure of the value of the system is not accurate. Third, the causal relationship of uncertainty. That is a certain cause, does not necessarily lead to a particular result. Such as natural disasters, policy adjustments, technological innovation, etc., will inevitably have an impact on the economic system, but this effect can bring what kind of results are not certain, but also with other known and unknown environmental factors and people's Adaptive ability is closely related. Fourth, the irregularities or randomness of economic volatility. Although people put forward a variety of cycles, such as the so-called Kiki cycle, Kondratiev period, etc., but the subjectivity is very strong. Each time the economic fluctuations are different in time and magnitude; economic fluctuations sometimes appear for longer periods, sometimes for shorter periods. It has been difficult to predict the future fluctuation period and range of the fluctuation period and amplitude that have already appeared.

Thus, the complexity of economic fluctuations leads to the diversity of knowledge of the economic cycle of the economy and the coexistence of multiple schools.

Third, the systemic reasons for economic fluctuations

The above discussion shows that the factors that cause economic fluctuations and other factors related to economic fluctuations are complex and interrelated, and that the effects of various causes are often repeated at different times and in different environmental conditions Change. From the perspective of economic theory, the reasons for economic fluctuations are multifaceted and there are many theoretical schools.

From the point of view of system science, it can be found that some factors are generated and persisted in the process of the system itself, while others have some chance or come from outside the system. The economic fluctuations determined by the internal elements of the system and their own movements are called "systemic causes" and are determined by the laws of people's production and consumption activities, such as physical and psychological needs of people, the profitability of behavior subjects, and the market Of the competitive characteristics and so on. These causes are the inherent dynamics of economic volatility, and fluctuations caused by these causes are known as endogenous fluctuations in the system. Endogenous volatility is determined by the law of the internal activities of the system under certain economic conditions. It can not be fundamentally eliminated by conscious behavior such as policy, although appropriate economic policies may alleviate the fluctuation to a certain extent.

Corresponding to systemic reasons is the "non-systemic reason". Natural factors are non-systemic causes, such as earthquakes. The impact from other external economic systems is also a non-systemic cause, such as changes in human factors such as international commodity and capital flows, policies and regulations, and changes in financial and fiscal policies, cultural conflicts, political changes and so on. Although these causes are generated within the system, but because of its occasional and sudden characteristics, the specific analysis can be regarded as non-systemic reasons.

It can be seen, although the systemic reasons are closely related to internal causes, but the two are not exactly the same. For example, SARS and 1998 floods are in the Chinese economic system, but not the general economic activities, and therefore belong to non-systemic reasons. Figure 2 is a classification of systemic and non-systemic causes. Two types of reasons are not absolute, there is a close relationship between the two, need to be analyzed according to specific issues.

Table 1 and Figure 2 illustrate a number of factors that may cause economic fluctuations, but whether these factors can contribute to economic fluctuations, as well as other related states of the system. Such as external shocks, but when the external shocks can cause large fluctuations in the scale is not necessarily certain. Therefore, the stability of the economic system is mainly determined by the structure and operation of the economic system itself.

In short, the economic system is societyThe basic components of the system are a complex self-organizing system. The complexity of human economic activity makes the economic system have special complexity. The complexity of economic system determines the complexity of economic fluctuation, that is, the multi-factor of economic fluctuation and the uncertainty of the relationship between various factors. From the perspective of system science, it is helpful to understand the complexity and uncertainty of China's economic fluctuation during the transition period, and to grasp the most important characteristic variables and the most effective control variables in the complex variables as much as possible.