Kondratiev waves

In the nineteen-twenties, Nikolai Kondratiev,

 a Soviet economist, who was a proponent of the New Economic Policy (NEP), which promoted small private, free market enterprises in the Soviet Union, concluded that capitalism was inclined to half-century cycles of boom and bust and boom again, rather than, as Marx believed, a single inexorable march toward collapse. Wrong answer. Stalin had him imprisoned and executed. It was the Austrian economist Joseph Schumpeter, he of “creative destruction,” who called these cycles Kondratiev waves and popularized them in the West. 

Kondratiev wave. 

Long wave theory is not accepted by most academic economists, but it is important for innovation-based, development, and evolutionary economics. Among economists who accept it, there has been no universal agreement about the start and the end years of particular waves. This points to a major criticism of the theory: that it amounts to seeing patterns in a mass of statistics that aren't really there.
Moreover, there is a lack of agreement over the cause of this phenomenon. Health economist and biostatistician Andreas J. W. Goldschmidt searched for patterns and showed in 2004 phase shift and overlap of the so-called Kondratjev cycles of IT and health (shown in the figure).