经济周期是国民经济运行过程中循环出现的上下波动的现象。长期以来,它一直是经济学研究的重要内容。世界各国的经济学家,包括马克思和恩格斯,对西方国家经济周期的研究,已有100多年的历史,并形成几十种内容不同的经济周期理论。这些理论对经济周期的产生、发展、传导机制、以及测定和对策作了比较深刻的研究。我们如果把经济周期理论的不同内容抽象掉,(暂且让我这样分析),可以发现,周期理论就是一种“两种力”的作用的“四阶段”模型。这种模型加进内容构成周期理论,用来分析经济发展,制定政策和战略则是一种方法。周期理论 Economic cycle is the phenomenon of fluctuations in the cycle of the national economy. For a long time, it has been an important part of economics research. Economists in various countries in the world, including Marx and Engels, have studied the economic cycle of Western countries for more than 100 years and have formed dozens of theories of different economic cycles. These theories make a more profound study on the generation, development, transmission mechanism, measurement and countermeasure of the economic cycle. If we abstract the different contents of the business cycle theory (for the moment let me analyze it this way), we can see that the cycle theory is a “four-stage” model of the role of “two forces.” This model incorporates the content of the theory of periodic structure, used to analyze economic development, the formulation of policies and strategies is one way. Cycle theory