We always plan too much and always think too little.
It is, after all, only common sense to realize that, but for the fact that economic life is a process of incessant internal change, the business cycle, as we know it, would not exist.
Those revolutions are not strictly incessant; they occur in discrete rushes which are separated from each other by spans of comparative quiet. The process as a whole works incessantly however, in the sense that there always is either revolution or absorption of the results of revolution, both together forming what are known as business cycles.
All we can thus far say about the duration of the units of [the business cycle] and each of [its] two phases is that it will depend on the nature of the particular innovations that carry a cycle,... and the financial conditions and habits prevailing in the business community in each case.