# “It’s Tough to Make Predictions, Especially about the Future”

A lot of people have said it, or something like it, though probably not Yogi Berra, to whom it’s often attributed.

Here’s another saying, which is also apt here: History does not repeat itself. The historians repeat one another.

I am accordingly amused by something called cliodynamics, which is discussed at length by Amanda Rees in “Are There Laws of History?” (Aeon, May 2020). The Wikipedia article about cliodynamics describes it as

a transdisciplinary area of research integrating cultural evolution, economic history/cliometrics, macrosociology, the mathematical modeling of historical processes during the longue durée [the long term], and the construction and analysis of historical databases. Cliodynamics treats history as science. Its practitioners develop theories that explain such dynamical processes as the rise and fall of empires, population booms and busts, spread and disappearance of religions. These theories are translated into mathematical models. Finally, model predictions are tested against data. Thus, building and analyzing massive databases of historical and archaeological information is one of the most important goals of cliodynamics.

I won’t dwell on the methods of cliodynamics, which involve making up numbers about various kinds of phenomena and then making up models which purport to describe, mathematically, the interactions among the phenomena. Underlying it all is the practitioner’s broad knowledge of historical events, which he converts (with the proper selection of numerical values and mathematical relationships) into such things as the Kondratiev wave, a post-hoc explanation of a series of arbitrarily denominated and subjectively measured economic eras.

In sum, if you seek patterns you will find them, but pattern-making (modeling) is not science. (There’s a lot more here.)

Here’s a simple demonstration of what’s going on with cliodynamics. Using the RANDBETWEEN function of Excel, I generated two columns of random numbers ranging in value from 0 to 1,000, with 1,000 numbers in each column. I designated the values in the left column as x variables and the numbers in the right column as y variables. I then arbitrarily chose the first 10 pairs of numbers and plotted them:

As it turns out, the relationship, even though it seems rather loose, has only a 21-percent chance of being due to chance. In the language of statistics, two-tailed p=0.21.

Of course, the relationship is due entirely to chance because it’s the relationship between two sets of random numbers. So much for statistical tests of “significance”.

Moreover, I could have found “more significant” relationships had I combed carefully through the 1,000 pairs of random number with my pattern-seeking brain.

But being an honest person with scientific integrity, I will show you the plot of all 1,000 pairs of random numbers:

I didn’t bother to find a correlation between the x and y values because there is none. And that’s the messy reality of human history. Yes, there have been many determined (i.e., sought-for) outcomes  — such as America’s independence from Great Britain and Hitler’s rise to power. But they are not predetermined outcomes. Their realization depended on the surrounding circumstances of the moment, which were myriad, non-quantifiable, and largely random in relation to the event under examination (the revolution, the putsch, etc.). The outcomes only seem inevitable and predictable in hindsight.

Cliodynamics is a variant of the anthropic principle, which is that he laws of physics appear to be fine-tuned to support human life because we humans happen to be here to observe the laws of physics. In the case of cliodynamics, the past seems to consist of inevitable events because we are here in the present looking back (rather hazily) at the events that occurred in the past.

Cliodynametricians, meet Nostradamus. He “foresaw” the future long before you did.