Social Complexity and Sustainability by Joseph Tainter

I promised a fuller review of this paper at the beginning of the month when I just pulled out the currency data (See

Did Rome fall because it was too complicated?

But interesting as that was there is rather more to Professor Tainter's work that is worth looking at.  His paper was published in a biological journal, The Journal of Ecological Complexity and is an attempt to look at historical phenomena from an ecological perspective.  In particular he looks at the rise and fall of the Roman Empire -a subject much on History Books Review's mind at the moment given the ongoing extended review I am doing of Gibbon at the moment.

Rome came to world prominence more as a result of its defeat of Carthage than of any other single episode in its history.  And at first sight, its victory was surprising.  The Carthaginians had been in the empire business for quite a few centuries before the Romans and had ample resources, in particular they had an efficient fleet and more than enough hard cash to employ mercenaries to deal with anything the Romans might throw at them.  Any rational observer who was inclined to make a prediction would undoubtedly have picked the Carthaginians as the likely winner.

Observers at the time like Polybius attributed the triumph of the Romans to some kind of unique grit in their character that enabled them to bounce back from setback after setback.  Tainter sees things differently.  He sees the very sophistication of the Carthagninans as their Achilles heal.  By having a complex society it became impossible for them to rapidly adapt to changed circumstances.  By contrast the agrarian Romans simply packed their bags and went off to fight.  They could and would stay in the field for as long as they remained unkilled.  Carthaginian generals by contrast had elaborate problems relating to pay, supplies and politics.

Having beaten Carthage the Romans settled down to mimic the very features of  Carthaginian society that made it vulnerable to Roman attack.  When Augustus left Rome a city of marble rather than brick he must also have created a profession of architects.  We start hearing about lawyers, poets and full time soldiers. There must have been quite a few mosaic designers around too.

And complex sophisticated societies can come up with impressive achievements.  The most impressive one in many ways was the Roman army, which was able to field several hundred thousand men full time year in year out for centuries.  Under normal circumstances the legions were unbeatable in both training and numbers.  Tainter regards the army as an example of problem solving.  The problem was maintaining the existence of the empire in the face of external and internal threats - and for a long period of time it was an effective solution.

But the productive capacity of the empire was finite and the cost of the army was high on the rest of society.  And the attacks on the empire were continual.  By the time of Diocletian and Constantine it was draining the resources away from most other activities.  We see an attempt to solve this problem in Constantine's restrictions on movement between professions.  Typically for a complex society the response to a problem is to increase complexity - in this case regulations.   As I have also discussed in my earlier blog post, inflating the currency was another.  Calls for increasing regulatory activity and resorts to complex financial engineering have a very contempary ring, don't they?

Meanwhile, the illiterate barbarians had a much simpler problem.  If they could get together enough of their poor but valiant friends to have a sporting chance against a legion, the empire offered big opportunities in the form of portable wealth.  It needed a lot of personal courage and a reckless disregard of danger, but it didn't require any planning or accumulation of knowledge, expertise and material.

If you track the barbarian invasions from the third century onwards you will see that the barbarians were rarely able to prevail against a determined emperor with his well trained and sophisticated military machine behind him.  (My upcoming podcasts are one option if you want to do that.)But every blow weakened the structure and also increased the complexity as the government tried more and more solutions to their problems.  In the end, the whole edifice collapsed.

If this paper is correct Rome fell simply because at the end of the day, running an empire of that size was just too hard.


Joseph Tainter Social Complexity and Sustainability Ecological Complexity 3 (2006) 91–103

This is on my Christmas list if anyone wants to get it for me.