Hi, welcome to Bookey.
In the 1920s, there was an economist in the former Soviet Union named Kondratieff who was an expert on econometrics.
At that time, this economic theory was proven right in many countries, and economic circles admired him so much that he was practically worshipped.
What makes us say this?According to Kondratieff's economic theory, the United States in the 1970s should have entered a period of economic downturn.
This was odd.