Traditional theories of business cycles:

目前存在有关发达国家经济活动周期的两个不同的论文。一个是实际的商业周期（RBC）方法（您将在第12单元中引入），另一个通常将经典商业周期（CBC）方向转移为除RBC以外的所有方法的伞。第一种方法（RBC）提出，经济活动的波动是由真正的冲击驱动的，而后者的工作（CBC）表明，现代经济是一种货币和金融体系，因此，随着经济代理的职位，周期是产生的。在金融市场。出于我们的目的，可以观察到，通过定量测试（不一定是理论驱动的），CBC方法并不是发达国家波动的解释。换句话说，在不求助于所谓的第一原则的情况下解释业务周期并非违法。这意味着，仅根据无限寿命的药物优化其跨期目标函数进行查询是不必要的。其次，实际部门与金融部门之间的二分法可能不适用于。请注意，商业周期是资本主义经济的特征。事实证明，总投资在大多数发达经济体中有助于GDP的大多数波动。

A stylised fact is that both a long and a short cycle in aggregate output can be discerned for both the prewar and the postwar period. The long cycle, of a length of six to nine years, is most pronounced for the structure of fixed investment. The short cycle, of a duration of three to four years, dominates the cyclical structure of inventory investment. The relative strength of these cycles is explained by the speed with which the associated capital stock can be adjusted. The speed is naturally greatest for inventories, intermediate for equipment and machinery, and the longest for building and structures. The term business cycle here is taken to mean the irregular periodic movement brought about by a first-order difference or differential equation.

The traditional approach to business cycles by and large emphasized real factors. Few and far between were the classical economists who satisfactorily (even to themselves!) integrated monetary and financial factors into their study of the rhythmic waves of activity that characterised capitalist economies. Thus, we record below three important moments in the evolution of thought on business cycles associated with landmarks in the subject. First is the seminal contributions of Richard Goodwin who pioneered the tools and techniques of dynamic economic analysis. Modern work in complex economic dynamics can be traced back to one or other of his papers. His models were cast entirely in real terms. Secondly, springing from the same Marxian stock, although developing his trade cycle by first grounding his framework in the monopoly capitalism of his time, is the theory of Michal
卡莱克。我们应该注意，波兰经济学家数学统计学家Kelecki是现代宏观经济学的创始元勋之一。因此，他的长期动态从他的短期动态遵循。基本包含的货币要素可以在中央银行的容纳立场上找到，这是商人投资计划提供的任何潜在客户。最后，在海曼·明斯基（Hyman Minsky）的工作中，资本主义经济是经济上层层的实体，容易在连接的财务和实际活动中波动。该清单绝不是详尽无遗的。例如，一组非RBC的业务波动方法是密集的。例如，丹尼斯·罗伯逊（Dennis Robertson）强调了循环的起源和传播中的货币因素。

Another illustrious member of that tradition was Ralph Hawtrey who underscored the importance of bank credit which is indispensable for carrying inventories. Reductions in interest rates induce businessmen to carry larger inventories. Greater orders, in their turn, encourage increased investment and, with a lag, investment in fixed capital.