What's that on the y axis again?
There are even numbers there, as though everything weren't just totally made up but it obviously is.
Skepticism is a very appropriate response. I am about as far from an expert on this topic as you can get but here is what I have found
in my own quite limited research.
Question #1 Is there any actual solid statistical analysis to show these Kondratieff cycles really exist.
I found this very interesting statistical analysis of Kondratieff waves.
https://escholarship.org/uc/item/9jv108xp#page-1These authors did a tremendous amount of work on Kondratieff waves or K-waves and world GDP dynamics.
Their analysis supports the existence of a K-wave with a period of 52-53 years with a level of evidence or p value between 0.04 and 0.05.
With data like this it cannot be argued that this is something totally made up. Advocates of K-waves may be wrong in their assumptions
or analysis or they may be wrong in arguing that any cyclical behavior seen in the past is predictive of the future but there is at least some
data to indicate that K-waves are real.
Question #2 Does K-wave analysis actually predict war
Here I have struck out. I have not found any source nearly as compelling as the the statistical analysis on GDP dynamics. I cannot answer your question
about the war cycle graph because I have not found a solid enough reference to back it up.