Why do Societies Collapse? Diminishing Returns are a key Factor, a new Study Says

In 1988, Joseph Tainter published a fundamental study on the collapse of societies, proposing the existence of a common cause, diminishing returns, for the fact that all past empires and civilizations had eventually collapsed. Recently, myself and my coworkers Sara Falsini and Ilaria Perissi performed a system dynamics study that confirms Tainter's ideas and goes deeper into the origins of the diminishing returns of civilizations. It was published now on "Biophysical Economics and Resource Quality"

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. 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.

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. 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?

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. Tainter attributes these diminishing returns to an intrinsic property of control structures to become less efficient as they become larger.  Below, you can see a rather well-known graph taken for Tainter's book "The Collapse of Complex societies." (1988)

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. 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. 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.

A 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. 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?

These and other questions are examined in a system dynamics study that myself and my coworkers, Ilaria Perissi and Sara Falsini, performed. 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. So, we built a series of models inspired by the concept of "mind-sized" models. 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. We found that on the basis of some simple assumption, it is possible to produce a curve that qualitatively looks like Tainter's one

The system dynamics model tells us that the origin of the diminishing returns lies in the gradual depletion of the resources that flow through the system. It is not so much an effect of increasing complexity in itself, the problem is sustaining that complexity.

Then, the model also tells us what happens on "the other side" of the curve. That is, what happens if the system continues its trajectory beyond the point where Tainter's curve stop. The curve shows a clear hysteresis, that is, it doesn't follow the earlier path, but it remains always on a low-benefit trajectory. It means that cutting on bureaucracy doesn't make the system more efficient.

These results are not the final word on the question of societal collapse. But they do provide some fundamental insight, I think. 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). If the EROEI goes down, then the system falls into the Seneca Cliff.

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 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. But, unfortunately, it is exactly what most governments in the world are trying to do. It is a good way to speed up toward the impending cliff.

What we should do, instead, would be to move as fast as possible toward a renewable-based society. 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. Too bad that nobody seems to want them.

There has to be something in the concept of "BAU" that makes it one of the most powerful attractors you can simulate in a system dynamics model. And so we are moving toward an uncertain future, but one thing that we can be sure of is that fossil fuels will not accompany us there.


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Our complete paper can be found here. You can also find an abridged version on ArXiv.

And here are the authors

Ugo Bardi

Sara Falsini

Ilaria Perissi








Note: an earlier version of this post was destroyed by the evil minions of the Great Satan -- that is by Google Blogger.

The age of diminishing technological returns: a review of "The Age of Low Technologies" by Philippe Bihouix

Atomic cars are a good example of too much technology (image from "secondchancegarage"). The concept of diminishing technological returns of is the subject of the recent book Philippe Bihouix, "The Age of Low Technologies" (In French, "L'Age des Low Tech")

Recently, a friend of mine showed me an app for his new smartphone. It is called "catspeak" (or something like that) and allows you to choose a message to send to your cat which, then, the phone will translate and vocalize in cat language. Unbelievably, it works! At least, my cats seemed to be very impressed by being addressed by the phone with the meowing meaning "go away" or "I'm angry at you."

This idea of speaking to your cat using a smartphone app seems to be the most egregious example I can find of the concept of "too much technology". Think of  the cost of modern smartphones in terms of precious and non renewable resources. Then, you can't avoid to wonder how is it possible that they are used for such silly purposes.

The concept of "too much technology" is the subject of the recent book by Philippe Bihouix (one of the co-authors of "Extracted") titled "The Age of Low Technologies" (In French, "L'Age des Low Tech"). Bihouix is a first class technologist, at ease in several different fields from electronics to biotechnologies. And his criticism of the naive enthusiasm of the public for the new gizmos presented in the media is simply devastating. He takes no prisoners in his demolition of some of the pet ideas of some fashionable technological gurus. Just read the section on nanotechnologies and, well, you'll see what I mean. The nanotechnologist has no clothes, really.


A consequence of diminishing returns is the phenomenon we call "peaking" as the result of overshoot when people misjudge the long term returns of their activities. It occurs with oil extraction and it also occurs with new technologies: they tend to "peak." They reach extreme performance and then slow down, adapting to a compromise between performance and cost. 

The best example of this phenomenon is, I think, with today's planes. They have noticeably slowed down from the time of the supersonic Concorde, to emphasize efficiency and comfort. The Concorde was simply too expensive to be a practical technology: it was a plane in overshoot. It is likely that something like that will happen to today's smartphones - right now, they are wonderful devices, but they are in a condition of  resource overshoot. In the future, we will not be able to maintain their extreme performance facing the increasing costs of rare mineral resources. That doesn't mean that smartphones will disappear (although that's not impossible) but it means that some kind of compromise between performance and cost will have to be reached. 

Bihouix's book is very much based on this concept: that is how it will be possible to balance performance and cost after "peak technology". It is a fascinating description of a world which moves a little slower than ours and which, of course, can't pretend to keep growing forever. But it is also a world rich of possibilities; not less interesting than ours and also better under many respects. 

A truly remarkable book - by all means recommended! There is only this small problem with the language, but, come on, don't you eat sometimes a baguette and drink café au lait? Then, "L'age des low tech" is worth of a little effort of deciphering! 



 

Cassandra changes name

In almost five years on the Web, "Cassandra's legacy" had a reasonable success, reaching an average of some 30,000 page views per month and a total of about 850,000 page views. But, as you see from the figure, in the past year or so, the number of contacts has been declining. Cassandra has peaked.

Many things have been changing in the world and it is time to take notice. We are seeing is a "leopard spot" pattern of peaking. Some countries are still growing, others have peaked and are declining. It depends on the availability of natural resources, on the structure of the economy, and other parameters. Countries which are importing most of their mineral commodities - such as Italy - are the most affected; others are doing better, so far. In any case, nothing ever remains the same. This blog, too, must change.

I have already changed the name of Cassandra's Italian sister - the blog named, today, "Effetto Risorse" (resource effect). I was sorry to discard the beloved Cassandra name but, with the new title, the Italian blog experienced a real boom in attention. Apparently, "Cassandra" has a negative ring to it. It is not Cassandra's fault, of course; after all, she had been always right in her predictions. But we need to take into account how most people feel, so a new name is in order also for the English version.

Accordingly, I renamed the blog from the title of my new book which will be available next month "Extracted". The name says it all, I think: we have extracted our way to prosperity but now we are entering an age of diminishing returns from extraction. We will have to learn how to live with less. This blog will explore this transition.

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Note added after the publication of this note. I received a few comments from people who think that the name "Extracted" doesn't really sound right. Which may well be the case: not being a native English speaker, I have troubles in getting the exact "feeling" of this or that word in English. So, the title of the blog can be changed (although not any more that of the book!). If you have ideas or suggestions, please let me know in the comments or write to me at ugo.bardi@unifi.it