There are two problems with the idea of business cycles.
I went to graduate school in economics to study business cycles in the early 1960s. The only work of significance that had been done was by the founder of the field Wesley Mitchell.
First, there is nothing cyclical about business cycles. They come in relatively short intervals but they are highly erratic in their timing.
Second there is nothing repetitive about them as the word ‘cyclic’ implies. Each one seems to be individual and distinct from every one else. No one has been able to identify any factors that are common to many.
In fact there is no such thing as business cycle ‘theory’ after 80 years of effort. There is one institution, the National Bureau of Economic Research, NBER, in New York that we accept as the arbiter of business cycle dates. After the fact, the NBER identifies the point at which the cycle turned down and the month at which it turned up. This is done by looking at the various indicators of commercial activity and looking for coincident movements that indicate the peak or trough. These coincident movements are never the same and highly eclectic.
There was one long-term business cycle theory, called the Kondratieff cycle. It was supposedly a period of 25 years of growth and 25 years of no growth or decline. While such fifty-year cycles can be read into history, it has not been visible in the past seventy years in the United States or the world.
Business cycle theory is not a viable theory and does not help us understand anything in economics. Unfortunately.