#DIMINISHING MARGINAL RETURNS SERIES#

We are lucky that we have energy technologies efficient enough in term of EROEI that they could support a transition to a better, cleaner, and more prosperous world. What we should do, instead, would be to move as fast as possible toward a renewable-based society.

It is a good way to speed up toward the impending cliff. But, unfortunately, it is exactly what most governments in the world are trying to do. If we want to keep alive some kind of complex society, we can’t do that by scraping the bottom of the barrel, desperately trying to burn what we can still burn. Of course, since our society depends on fossil fuels, we are bound to go that way because the depletion of the best resources is progressively lowering the EROEI of the system. If the EROEI goes down, then the system falls into the Seneca Cliff. It is the fact that the system is “alive” as long as its resources provide good returns - in terms of energy resources, it means they have a good EROEI (energy returned on energy invested). But they do provide some fundamental insight, I think.

These results are not the final word on the question of societal collapse. We found that on the basis of some simple assumptions, it is possible to produce a curve that qualitatively looks like Tainter’s one. That is, models that don’t pretend to be a detailed description of the system but try to catch the basic mechanisms that make the system move and, sometimes, go through tipping points and collapse.

#DIMINISHING MARGINAL RETURNS SERIES#

So, we built a series of models inspired by the concept of “mind-sized” models.

The idea is that if a civilization is a complex system, then it should be possible to model it using system dynamics, a tool specifically designed for this purpose. These and other questions are examined in a system dynamics study that myself and my coworkers, Ilaria Perissi and Sara Falsini, performed. One question you might want to ask is: fine, there are diminishing returns, but where is the collapse in the curve? Another one could be: if the system experiences diminishing returns, why doesn’t it just retrace the curve to go back to where it was before? Barbaric invasions, for instance, are not the reason that led the Roman Empire to fall, the Barbarians just exploited the chance they saw to invade a weakened empire.Ī problem with Tainter’s idea is that it is qualitative: it is based on the available historical data, for instance, the debasing of the Roman currency, but the curve of the diminishing returns is just drawn by hand. If Tainter is right, then the many phenomena we observe during the collapse are just a reflection of an inner sickness of the society undergoing it. Tainter’s idea is fascinating for several reasons, one is that it generates some order in the incredible confusion of hypotheses and counter-hypotheses of the debate on societal collapse. Below, you can see a rather well-known graph taken for Tainter’s book “The Collapse of Complex societies.” (1988)

Tainter attributes these diminishing returns to an intrinsic property of control structures to become less efficient as they become larger. One of the most fascinating interpretations of the collapse of civilization is Joseph Tainter’s idea that it is due to “diminishing returns.” It is a well-known concept in economics that Tainter adapts to the historical cycle of civilizations, focusing on the control structures designed to keep together the whole system, the bureaucracy for instance. Is there a single cause for these collapses? Or is collapse the result of many small effects that, somehow, gang up together to push the great beast down the Seneca Cliff? There are, literally, hundreds of “explanations” for the decline and fall of empires, and the same confusion reigns for the fall of the past civilizations rising to glory and then biting the dust, becoming little more than ruins and footnotes in history books. The underlying question in Gibbon’s massive study was ‘are we heading for the same destiny as the Romans?’ A question that generations of historians have tried to answer, so far without arriving to answer on which everyone would agree.

Why do civilizations collapse? It is a question that has been haunting the nebulous entity we call “The West” from the time when Edward Gibbon published his “Decline and Fall of the Roman Empire,” in 1776.

Diminishing marginal returns