This Is the End


Markets, Risk and Human Interaction

December 10, 2012

The Great Migration of the 21st Century

One lesson we should keep in mind as we recover in the aftermath of Sandy is that we are slow learners. Although the vulnerability of many of these communities is undeniable, we have resolved to rebuild the homes. That resolve will no doubt weaken if the region is revisited by similar disasters, and those displaced will be forced to move on. If climate change is at the root, that will happen. There will be a crescendo of such disasters, replaying thousands of times in populated areas across the globe. Hurricane Sandy thus has given us a glimpse into what will be the dominant theme of the twenty first century: forced migration.

Historically, migration has been driven by need, such as a disparity in economic situation, or because the migrating group reached the limits of the land given population growth. The migration may be into uncontested, virgin land; what is referred to as wave migration. Or it may be migration into other populated areas, which can lead to a new elite displacing the existing elite, to changes in status and a redistribution of wealth, but with the two societies existing side by side. A third type of migration, prominent in the barbarian period in the first millennium CE, is not based on economic need or population constraints, but on a nomadic culture pillaging the riches of the lands they invade. The first two are demand-pull, the third is supply-push.

I can envision any of these migration models playing out in the next century. Gradual migration and assimilation, or a gradual replacement of the indigenous population with a new elite, or one of invasion and warfare. Or wave migration; less likely but particularly interesting because the very effects of climate change will open up new, previously uninhabitable land even as flood and drought make other land uninhabitable. The plot of James Bond's “A View to a Kill” comes to mind; there the villain planned to trigger a massive earthquake that would plunge most of the California coastline into the sea, turning his holdings of inland desert into new, prime oceanfront real estate. Climate change and rising sea levels replaces the earthquake and villain with an alternative plot.

How bad can this sort of thing get?

The Last Great Migration: The Barbarians
There has been revisionist history over the past decades recasting the invasion of the barbarians; the use of the term migration in place of barbarian invasion is representative of this shift. And the barbarian invasions were a great migration. But it may be too early to discard the view, depicted in accounts of the time, that the feudal Europe we recognize emerged from the wave of a thousand years of invasion and ethnic cleansing.

The headline statement for this period is that the barbarians laid waste to everything, and over time forest and swamp intruded where there had been civilization. By the ninth century, there were miles of formerly populated countryside devoid of people, and those in one village lived their lives with little knowledge of other villages. In Spain the Vandals divided the country among themselves, but not before they destroyed the land. When the Goths conquered the Vandals, they fled from Spain, crossed the Straits of Gibraltar to Africa, and continued with unrelenting ruthlessness. A contemporary writer gives this account:

They carried their destructiveness into every corner of it; they dispeopled it by their devastations; exterminating every thing with fire and sword. They did not even spare the vines and fruit trees, that those to whom caves and inaccessible mountains had afforded a retreat, might find no nourishment of any kind. Their hostile rage could not be satiated, and there was no place exempted from the effects of it. They tortured their prisoners with the most exquisite cruelly, that they might force from them a discovery of their hidden treasures. The more they discovered the more they expected, and the more implacable they became. Neither the infirmities of age nor of sex; neither the dignity of nobility, nor the sanctity of sacerdotal office, could mitigate their fury; but the more illustrious their prisoners were, the more barbarously they insulted them. The public buildings which resisted the violence of the flames, they leveled to the ground. They left many cities without an inhabitant. When they approached any fortified place, which their undisciplined army could not reduce, they gathered together a multitude of prisoners, and putting them to the sword, left their bodies unburied, that the stench of the carcasses might oblige the garrison to abandon it.

The barbarians were equal opportunity destroyers. No matter what their station, those who survived their invasions uniformly found their living standards diminished as this migration proceeded. The Barbarians were rural and to some extent nomadic, mingling agriculture with hunting and herding. If the land became exhausted, they moved on to clear virgin land while the forest closed in behind them. They lacked many techniques for cultivating and preserving the land. They used slash and burn methods which quickly led to diminishing yields. Before the migration, under the late Roman Republic, the average yield in Italy was four times the seed. After the migration, in thirteenth-century England, yields were at least three times the seed. But in the barbarian age the largest harvests were twice the seed, the lowest ones fell below one and a half times the seed. This means that at least half of the cultivated area served to produce seed, a dearth in production compared both to what existed before and what would exist thereafter.

But, on the bright side...
The barbarians brought about some equalization for the lower classes. Social inequality grew dramatically during the Roman period; ancient Rome had rich aristocrats and well-off freeman farmers, but also had landless laborers and slave labor. The long depression of the barbarian age fostered the growth of a new, intermediate class that combined the now landless freemen and the freed slaves. This new social group became the serfs of Feudal society. The reduced efficiency in agriculture increased the demand for labor; there was work for every man. Indeed, labor often was in such short supply that the landholders had to bid for their services. So, strangely, the barbarians became a leveling force for society even as they broadly diminished the standard of living.

Anyone who lived through the life cycle of the baby boom knows two things about demographics. First, demographic cycles are slow but inexorable. And second, perhaps because they move so slowly, they are often ignored. It was obvious with the emergence of the baby boom post-World War II that over the course of the next five to ten years there would be a tidal wave of bodies coming into elementary schools, and that in ten to fifteen years that tidal wave would hit high schools, then colleges, then the housing market. Yet we lived through split sessions because schools were not built to accommodate this boom, even though there was more than adequate lead time. (And many of the schools that did get built then were torn down once the baby boomers move past school age, just in time to miss the next demographic wave – the children of the baby boomers).

Climate change will progress at an even slower, imperceptible pace. And unlike demographics, where the changes in birthrates are undeniable, climate change exists in a cloud of uncertainty. Not only do some question its existence, but even those who take it as a given cannot clearly project its course. The point is that we miss even the obvious risks if they move slowly enough, and the realities and effect of climate change remain less than obvious. And there are few risks that are as slow moving but substantial as those associated with climate change. The frog in the pot is the operative analogy.

Barbarians overran Europe as far as Scotland to the north and Portugal to the west; the land was carved up and administered by this new elite, with the original landholders displaced and the laborers becoming serfs. The Burgundians and the Visigoths took two thirds of their respective conquests, each Burgundian housed as a “guest” with the former landholder now living in a small part of his former estate. The Vandals seized the best land in northern Africa with no regard for the former inhabitants. The Lombards in Italy took a third of the land. The Franks took possession of much of the land in France.

The newly arrived became lords of their holdings, the previous tenants and farmers became their serfs. In the end this great migration gave us the Feudal Age, a social order that defined Europe for eight hundred years. What will appear a century hence, after the great migration on which we are soon to embark?


  1. Rick, enjoyed your essay, although your sense of late antiquity I find a little disturbing. There were a lot of important events and trends that took place between the irruption of the Germanic tribes and the rise of serfdom, and it is not really accurate to cast the indigenous folks in the western provinces (mostly Celts) as serfs-in-waiting or to draw a straight line between these two events. To the best of my knowledge, things didn't happen this way. You might find interesting the following texts on the subject: Julia M. H. Smith's Europe After Rome; Stephen Mitchell's A History of the Late Roman Empire; the encyclopedia Late Antiquity: A Guide to the Postclassical World; and some good older texts, too, like Blackwell's The Peoples of Europe series, esp. the volumes of the Bretons, Franks, Lombards, and Spanish. Also check out Norman Davies' Vanquished Kingdoms...he has some very interesting things to say about how some polities emerged during late antiquity and early medieval Europe.


    1. I am sure I am missing a lot about this period, and I am further constrained by painting a picture in a few paragraphs. As I mention, recently historians, (e.g., Peter Heather), have taken a more charitable view toward the barbarians, and suggest more of a symbiotic relationship with the indigenous people, though principally focused on Rome. And no historian will now use the term the "dark ages" for this period. But compared to what proceeded it in the centers of civilization, and what came thereafter with Feudal Europe (new modes of power, time keeping, merchants and trade centers, and agricultural improvements such as the heavy plough and new harnessing methods), it was not exactly a golden era.

  2. Good essay but it does not explicitely define who are (going to be) the new barbarians and what territory will invade? Could you be more specific please?

  3. The definition of the new barbarians would include those who can (via access, by ability, etc.) manipulate the game through knowledge that the underlying complexity will most likely shield their introduction of 'lemons' despite efforts by the "non-barbarians" to be vigilant and to prevent such gaming of the system. Evidently, it works. As in, where are the perp walks?

    See Princeton's FAQ on the subject of computational complexity and financial products: Computational Complexity and Information Asymmetry in Financial Products.

    The net effect can be a huge pocket-picking of the multitude of the hapless by the very few.

  4. Very interesting, thanks. I noted however that you seemed to limit your definition of 'forced migration' to being caused either by disasters or economic factors, presumably reflecting the context of Sandy and your interest in finance and economics. I wonder whether this somewhat confuses the admittedly already blurred distinctions between 'migration' and 'forced migration' (and the central role of conflict in triggering forced migration). By the way, given your interest in economics... I edit a magazine on forced migration - Forced Migration Review - and in our latest issue we publish an article entitled 'Are refugees an economic burden or benefit?', written by a colleague Professor Roger Zetter (relating to a research project with the World Bank). It's online at if you'd like to take a look.

    1. We might want to differentiate one type of barbarian here: invaders. We do have nature as the largest invader of our accustomed lives. One would hope that we got smarter about living with the beastly powers, thereof. But, dominance through military power has been a constant threat, too. Then, we have invasions that make this threat real. There were so many examples in the 20th century.

      As we know, the 'barbarian' is your unfriendly, uncouth (both requiring further definition) neighbor whether or not he, or she, encroaches upon your space. Yet, those Rick uses as examples were, many times, rolling hordes who did not seem to settle until they hit some natural boundary (water) or resistance (which we know was put up many times by the Eastern front of Europe - do we ever thank them enough?). As well, the hordes tore down more than they built. Rick's suggestion that their encroachment, and destructive ways, helped lift, somewhat and eventually, the lower classes is something that we ought to look at further.

      And, the tearing down does not have to imply physical demolishing. Heavy cultural changes can be as devastating to the lives of people.


      As an aside, were the Viking raids in the British Isles motivated by migration, sheer fun, conquest, or economics? All the above? Then, we have William I (the invader, thereby barbarian?) carving up his conquered land and giving it out to his buddies. In fact, my research right now deals with forfeiture's role in the history of families. Yes, as in, the king giveth and the king taketh away. Many times that led to eventual exits, such as the Great Migration to New England.


      Do we see an ultimate end of the invader type, at least human to human, with the advancement of military prowess everywhere?

  5. The new barbarians are the robots/AI computers. Check the latest views by Krugman

    and related inteersting stuff here:

  6. Rick's wide-ranging interests can be seen in the variety of subjects found here. Too, his twist is interesting.

    Reading the post and the comments, especially that from Marion, pushed me to look at the issues, again. Of course, we all know of the social upheavals; the press does a good job in their shallow fashion. We also know the failings of the elite classes in dealing with the matter (Rwanda comes to mind as one instance of many). Some (are these the barbarians?) seem to want to perturb things even further.

    It was nice to be reminded that people are looking at the problems and their possible solutions from a stance that is sensitive to, but removed, from the everyday hassles on the several sides: the migrant, the charity worker, the taxpayer, those being encroached upon, ... In other words, academics are involved.

    Is the magnitude beyond comprehension? To wit, consider this effort by the Wikipedia editors to enumerate the instances, albeit over a historic time frame. The list does include recent occurrences.

    Are there any movements caused by natural phenomena on the list?

    Adding in Marx, Schumpeter, et al, (Creative destruction), plus the unknown influences from computation (its potential exploitation by the barbarians and its own propensity to get out of our control - nod to Alan's 100th), increases the turmoil almost to intractability. No wonder we all have our heads in the sands of FB and such.

  7. Two issues. First, there's the problem of climate (dryer weather) between the fourth and eighth centuries, leading to shorter growing seasons, smaller yields and shrinking pastures(nothing like a shortage of grassland to get nomads on the move). Second, there's a biological problem: pandemics in the second and fourth centuries which may have reduced the Roman Empire's population by a fourth, topped by the (bubonic) Plague of Justinian in the mid-sixth century, which recurred at intervals in the Western world for the next 200 years. Depopulation led to widespread abandonment of agricultural land which frequently reverted to swamp (especially in the Mediterranean region), so causing malaria to become endemic in many areas.
    One additional point. Barbarians (Ostrogoths) may have taken over Rome in the late fifth century, but the devastation which brought classical Rome to an end was actually caused by the Eastern Romans (Byzantines) trying to retake it from the Ostrogoths.

  8. Nice essay, but the point is moot. Global Extinction within one Human Lifetime as a Result of a Spreading Atmospheric Arctic Methane Heat wave and Surface Firestorm.( Holidays.

  9. It would seem that the big global banks are the modern-day equivalent of the Barbarians... they certainly have looted and raped as they pleased.

  10. I believe that was Lex Luther's plan in the original Superman, not Max Zorin's. He wanted to flood silicon valley in order to corner the computer chip market. Just had to clear that one up. Thanks.

  11. Tie migration and your virtual concepts together. Maybe there will be select places to live in v-space, or the lords will control the servers.


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