In his book “The Collapse of Complex Societies,” anthropologist Joseph Tainter examines why civilizations such as the Roman Empire fell apart. Rome was powerful and seemingly invulnerable to decline, at least to its inhabitants. But as we know from our vantage point, it did undergo decline then collapse. So what happened?
The two key concepts in Tainter’s explanation are complexity and diminishing marginal returns. All societies start out simple, but some find reason to become more complex, as complexity “buys” solutions to problems that the society faces. In his words, complex societies are problem-solving organizations, in which more parts and more kinds of centralization and control emerge as circumstances require (Tainter, p.37).
But at some point, the rewards of increasing complexity peaks and begins to fall. Each increment of complexity buys less and less benefit, to the point where the society is simply trying to maintain the status quo. As problems pile up, attempts to solve them become more expensive and may make them worse. In the end, it is easier to return to a simpler state.
Although he cites a number of examples – the Mayans, the people of Easter Island – the classic example is the rise and fall of the Roman Empire. Rome grew from a small village on the Tiber River to an empire stretching from Britain to Africa, with tens of millions of inhabitants, then collapsed. But how and why did this occur?
After a number of military disasters, the Roman army was professionalized and expanded. Rome was built by its legions at the expense of neighboring peoples. The loot from these conquests paid for the army, public works, a public dole and an extensive bureaucracy that was tasked with administering an expanding, far-flung empire.
But expansion ended when conquest stopped paying for itself. Rome had run into a problem – lands beyond the frontier were poor and their inhabitants stubborn adversaries. Rome saw a net loss in trying to administer far-off provinces such as Britain. Germanic tribes were not worth the price of conquest, and constantly menaced Rome’s borders.
To pay for an enlarged army and increased administrative costs, latter emperors raised taxes on an already poor peasantry, who were ravaged by plague and barbarian incursions. Eventually, their labor was conscripted even as their numbers declined. In order to stretch the currency, emperors debased the currency, leading to inflation. Political effectiveness was undermined through internal conflict and rigid bureaucracy.
The Western Empire, weakened by economic stress within and foreign invasion without, essentially ceased to exist with the deposing of the last emperor in 476 AD by a Germanic chieftain. By some contemporary accounts, the peasantry welcomed the collapse and the relief it brought to their burdens.
Of course, this is a simplified explanation both of Tainter and of Roman history. I invite readers to read his book and watch his lectures on YouTube for further detail. I think his views offer some insight into the challenges we face as a nation as we face global instability, political ineffectiveness here at home, and resource depletion.