Stages And Causes Of The Business Cycle
According to Burns and Mitchell(1946), who were the first that investigate the modern research methods of the economic fluctuations, economic fluctuations is a continuous model of recession, recovery, growth and decline of the economic activities around from a long-term trend. The continuous character of this model justifies the expressions 'cyclical fluctuations' and 'business cycle' although the movements have neither constant duration nor constant length.
The perception that the economists had about the economic fluctuations changed with time and differs according to different schools of thought(the economic science is a social science and all the social sciences have political economy flavour).
Before Keynes, the researchers of the economic fluctuations observed prosperity periods and crises periods. However, in 1930 economists understood that this discrimination didn't express the reality because during the growth period it is reasonable that there will be prosperity .However, it is also possible for the prosperity to coexist with unemployment , an indicator that is in the core of the crisis. That has an a consequence these two expressions (prosperity and crisis) to be replaced with the expressions 'peak' and 'trough'. The peak corresponds to the maximum point of GDP of the last time period of the economic growth. Similarly, the trough corresponds to the last time period where there is reduction in the economic activity.
I would like to define and explain some terms that I will use to my later analysis and are fundamental in the understanding of the business cycle and the economic fluctuations.(责任编辑：BUG)