Plagues & economic collapse by Ian Morris

good evening and welcome to the 7th of the 2014 Darwin College lectures which is on the broad theme of plagues and welcome to all of you here tonight on this day with bad traffic jams outside and also the many thousands of people who will watch these lectures later on on the web without having to be concerned about a traffic jam this is as you well know a very important year for Darwin College as we celebrate the 50th anniversary of the foundation as the first College in the University of Cambridge exclusively for graduate students and also the first mixed college and from a small beginning we are now amongst the largest colleges with an alumni body that encompasses every subject and is spread right around the world now this evening I'm very pleased to welcome our lecturer Professor Ian Morris who's going to consider the economic aspect of play plays Ian studied archaeology as an undergraduate at Birmingham University and then moved here to Cambridge for his PhD and a fellowship and then on to a faculty position at the University of Chicago so returning here to Cambridge he is very much in his old horse then in 1996 he became the Jean and Rebecca Willard professor of classics and archaeology at Stanford University his research interests have broadened over his career from ancient Greece to global questions about world history he's an author of a good number of books his book why the West rules for now won three international Book Awards was named a 2010 Book of the Year by The Economist was one of the hundred most notable books of 2011 by the New York Times and one of the best reads for 2011 by Nature his 2013 book is the measure of civilization how social development decides the fate of Nations well our plagues always really damaging for societies for other circumstances under which a society can advance after a plague ian is going to examine and compile examples of historic and ancient plagues and seek to predict how the economies of our 21st century might respond to plagues so I very warmly welcome professor Ian Morris to speak on plagues and economic collapse [Applause] [Music] well thank you and thank you for turning out on this and another gloomy day it's it's great to be here I'd like to thank everyone for inviting me to give this lecture and it's it's nice to be in here I have vivid memories I was just just saying before we came over vivid memories of sitting in this room listening to Ernest Gellner to one of the Darwin lectures in which was apparently in the very first season of them many many years ago this was to be my 1986 or so but anyway I've invited em here this evening to talk about plagues and economic collapse and I'm gonna be focusing on me down on one question which is you do plagues cause economic collapse and the answer I can tell you is a resounding sometimes severs and her husband 50 minutes tell you about that so it's a question that you if you're coming into this from a historical angle it's a question where there's no shortage of sources to work with so I'm looking at this in many plagues throughout history a lot has been written about them by people who lived through them and generally they all seem to have pretty similar attitude that the world is ending so you read the material written by the people who experienced the plagues and they gather their own very resounding answers the question about about collapse only the most famous of the people who wrote about this era brightening even khaldoun lived through the black death in the 14th century and he pretty pretty forcefully a civilization in both the east and the west was visited by destructive plague that devastated nations and caused populations to vanish it swallowed up many of the good things of civilization and wiped them out so eben Khaldoon in no two minds about this topic and this city are fairly common sense reaction to a plague but I think in fact when you look at the long term history of plagues clearly there's a bit more going on here and my general sense of the picture is that you you can't really say the plagues cause economic collapse although they certainly can be involved in collapse sometimes they they do seem to be a play a part in this and I come to this question as a historian and an archaeologist and you know as you just heard I began my life as an archaea just of ancient Greece here I'm beginning as an archaeologist of ancient Greece who is this handsome brute you ask wise yes sir that is me back in 1989 digging on a site in Greece and I started off focusing on the rise of ancient Greek city-state between about 1000 and 500 BC and um I've been having us a trip down memory lane this week on Wednesday I gave a talk at Birmingham University where as an undergraduate they haven't been back on the campus there in over 30 years so that was just very very weird and now here I am we're also a graduate student and I spent today meeting with some of my old buddies from the old days and I'm sure some of you will know Paul cartilage and Peter Ganzi and my dissertation adviser antony's Snodgrass some of the the leading lights of classical archaeology so it's been very nice to be back but as I used to went on being a classical archaeologist one of the things I noticed early on in my own work was it as if I broaden the perspective on things that I was interested in problems I was trying to deal with it often changed the way I saw the problem and new Answers started to appear and as time has gone on I found of taking a broader and broader perspective on the work that I'm doing after starting off digging mostly in ancient Greece itself I ran for some years an excavation after the western end of Sicily and another beautiful place one of the great things about being a classical archeologist is all these guys live near the beach and there are very sensible ancient people so I found you're broaden the perspective the geographical chronological perspective tended to open up new answers to the old questions but I found what it also did was it started to push new questions onto me I started to feel more and more you're not just does this give me a new way of seeing an old problem but it suggests a whole new set of problems and the old problems often started to seem just a little bit small compared to the problems that were being opened up by a larger perspective and in the process I also found are showing very appropriate tonight I became more and more of a Darwinian as this went on I think that the bigger the scale you look at history on the harder it is not to think about it in evolutionary terms although some people do manage but they are just wrong so I said moved in this direction and a few years ago I wrote the book that was mentioned just a moment ago book called why the West rules for now where what I tried to do in that was I tried to look at fifteen thousand years of history to try to get some sense of why it was a fairly small group of Nations around the shores of the North Atlantic came to dominate the whole planet in the last couple of hundred years and in the process of writing this book the way I went about it was to construct an index of social development so to measure how these societies developed over time and I raised that I'm going to come back to that in just a moment we'll be drawing on this a little bit tonight but what I was doing in this book was looking at the big trends in world history and saying you know can we identify the transitive driven the historical process can we project them forward to talk about where they might take us next and can we also see what kind of forces and derailed these trends in the past can we identify your what caused the big collapses in that that's big social collapses and I thought there was a pattern you could see whenever you dealt with big social collapses in history the same group of forces came up again and again in almost all the cases when you look at these collapses and I cheerfully called them the five Horsemen of the Apocalypse and one of the mass migration would be a migration on a bigger scale than societies and institutions could cope with often as a consequence of this you would get huge epidemic disease is often driven by the merging of what a previously been separate disease pool so they come together and no one really has many of the antibodies they need to defend themselves against these diseases you get massive kill offs often as a consequence of that state failure the government's just can't cope with what's going on things fall apart often a consequence of that famine follows on the back of it the trade routes dry up thousands millions of people starve and then always mixed in somewhere although always in different ways and climate change always seemed to be a part of these things so okay so these things come up again and again together of the the epidemic disease it was the most famous example of this kind of collapse the big epidemic disease involved is the the urban Khaldoon plague that I saw enough talking about in the 14th century the Black Death possibly began as early as 1331 in Central Asia certainly by the 1340s it's raging across a wide area of the old world kills estimates vary killed somewhere between one third and one half of the population in your about western end in the middle do I have a pointy thing in this well I can't figure it out anyway but what do you know where the Middle East is who really needs a point though a third to half of the population in Europe the Middle East and China and it seems not to have seriously impacted India Southeast Asia Japan sub-saharan Africa the Americas so it's a it is select part of the world that massive kill off goes on devastating effects some IBN khaldoun sentiments echoed over and over again and here's an Italian writer Matteo Villani lived in Florence during the plague as far as can be found in written records there has been no more widespread judgment by mortal illness from the universal deluge to the presence nor one that embraced more of the universe than the one which has occurred in our own days devastating immortality but did it cause an economic collapse the you know most famous plague in history did this caused an economic collapse my topic tonight basically as so often an academia it depends on what you mean by an economic collapse and there now come to the if you want to step out for a moment the the compulsory boring part of every lecture where you have to define what you're talking about explain what some of the terms mean and obviously if we're talking about plague and economic collapse these are terms that we do have to decide what exactly we mean by them with economic collapse this is now coming back to this thing about social development they mentioned earlier they can construct this Development Index or one of my earlier books basically what I meant by social development was society's ability to get things done in the world and I put it a bit more formally in in in my books and although one of my pet hatreds is people who read out PowerPoint slides I'm not going to do that anyway because I can really and I think this is a useful way to approach the issue of economic collapse and a useful tool for definitions and basically what I got in mind by Social Development is the bundle of technological subsistence organizational and cultural accomplishments through which people feed house clothe and reproduce themselves explain their world around them resolve disputes within their communities extend their power at the expense of other communities and defend themselves against others attempts to should be extend their power a little bit very broad thing but basically a group's ability to master its physical intellectual environment and use this mastery to get what the people want from the world and in principle at least I think this is something that can be measured and compared across space and time and I am expounded at enormous staggering lengths in fact in another book that was mentioned the men's book the measure of civilization where I go into a ridiculous level of detail about how I constructed its index and then the evidence I used so I won't bore you with any of that stuff tonight because you know even to me this is actually extremely dull stuff I won't bore you with it how I went about it but the reason I bring it up is I think this is a useful metric to allow you to establish in what you are using as the limits of economic collapse what the phenomenon is social development of falling social development is clearly a form of collapse having a numerical index allows you to sort of play around a setting different thresholds I mean there's no right or wrong answer how much does development have to fall before you talk about it to collapse you can decide for yourself what you think and that should be but having the numerical in the index allows you to say well you know what happens if we set the threshold as a at 10% collapse the decline that counts as a collapse or a 5 percent over 20% you sort of play around with this so for the sake of argument I thought well let's say we'll count situations where social development falls by 10% we'll count that as being a serious collapse now by that standard and the black death of the 14th century meets that the area for for counting as one of these collapses although only just and here is a graph of some of my numbers dates along the bottom Social development's scores on the vertical axis the blue line representing western parts of the world the red line representing Stern parts which another thing you can argue over the definitions but I think we don't need to get into that right now but I bury this 10% cut off the black death 14th century would just about qualify as having triggered a collapse the eastern and western Social Development scores each fell about 11 percent across the 14th century as I calculated them but this is where I think it becomes interesting if we extend out our time scale beyond the Year 1400 we see a rather peculiar thing about the Black Death the most famous of these plagues after there's 11 percent decline in Social Development in the 14th century across the next 400 years both of these regions seem really quite spectacular increases in development in the eastern part of the world development rises by 39 percent between 1400 and 1800 in the western part it shoots up by even more than that I mean these are extraordinary improvements i seventy one percent are something that the Western score rises by this is the biggest increase across a 400-year period up to that point in history that I was able to identify so what we get from this well one possible conclusion would be that in this case plague leads to collapse and then greater recovery that plagues are bad in the short run but got in the long run that's one possible interpretation to read into this now listen in fact this is sort of how European historians have looked at the black test for quite a long time even before they had the benefit of my Social Development Index and if you look back in a classic tome like the Cambridge economic history of Europe this is sort of the way it talks about the Black Death or the French and a least historians in the mid twentieth century and you broadly they take a kind of Malthusian approach to this that plagues tend to break out when population is pressing against subsistence limits they sharply reduce the number of people and the result of this is a bounce back after the play they're broadly Malthusian take and lots and lots of Western European sources talking about the Black Death talk about it in very much these terms I say the plague just changed everything that plague shook up social relations enormous Lee and a lot of the best evidence about this actually comes from right around this area from Cambridge and Ely and whether the great peasants revolts breaks out around here in the late 14th century the King has to come and meet with revolting peasants great changes in social order begin the late 14th century so lots of historians thinking of this is very much what happens you collapse and then a greater revival and this I think is one of the ways in which when you start looking at these things on a longer time scale that sort of broadly Darwinian evolution we framework is very very unhelpful I mean one of the things that evolutionists like sometimes as social as well as biological sometimes I like to talk about it to say that you can think of evolution as operating in the fitness landscape is there the term people will often use and they'll say you imagine here's a diagram I stole from somebody else's book you imagine we've got a sort of graph kind of thing going here and the vertical going up is a level the level of the excellence of adaptation of an organism or society to its environment your evolution is a path dependent kind of thing you can't suddenly sprout a third arm because it would be useful you just can't do that if you don't have the prior third arm that's available to you you can only sort of go up out of the track you're in so therefore each kind of species of animal each society it's developed down a certain path you can carry on moving sort of up the hill on this diagram becoming better and better evolved to fit in with its landscape but even though there's a possible peak you can see up at the top in the middle of the graph there of an organism or a society that could be much better adapted to its landscape its environment than the ones that actually exist the ones that actually exists as a railway track looking things they can't get over there because you can't um you you're not going to evolve toward a less for adaptation to your landscape because that would not be evolution you're not going to happen I mean the only way you can leap up to these potential higher Peaks would be if something happens to level this Fitness landscape and this social evolution is sometimes suggest this is the way plagues work this is that the collapse then the recovery phenomenon they level the old hills and societies move off in new directions and what historians have suggested over and over again is what happened to the Black Death is it's really the death knell of feudalism this collapse in population allow it clears off the landscape allow societies to start moving toward capitalist forms which turn out to be much better adaptations to this environment and by 1500 populations recovering sharply in Europe but some societies have begun to take on very new social relations and the capitalist take-off begins so out of the collapse at the end of the black death comes growth so this has been the standard story for a long time but over the last 40 years or so there's been this series of challenges to which I think complicates the picture in sort of interesting ways and back in the 1970s a Marxist historian a guy named Brenner came up with what became known as the Brenner hypothesis and what Brenner did was he said let's look at the Black Death but instead of doing like everybody does and focusing on Cambridge and Ely and paris basically let's look at the whole of Europe so a very varied fitness landscape now and what happens he says well what we find when we look at this larger scale because different outcomes proceeded from similar demographic trends at different times in different areas of Europe the same pressures of population could and did lead to changes in the distribution of income favourable to the laws or the peasants opposite outcomes depending on the social property relationships and the balances of class forces so a a little bit of that 1970s Marxists speak in there but you're basically what he's saying is that it all depends and the Black Death in some places led to the take-off of capitalist institutions in other places it didn't you're depending on where a particular society was in the fitness landscape you got wildly different results when the population collapse and basically west of the Elbe River in Europe you get the take off of capitalist institutions east of it you don't you get what is storming something called the new feudalism Poland Russia all kinds of other places feudalism revives much more strongly now in the last fifteen or twenty years a new set of ideas driven by by new evidence about the impact of the Black Death and this has come under seemed very very strongly historians have succeeded in putting together very long series of data on real wages in different parts of Europe in particular and this is pushed and he pushed people to think in new ways about the Black Death and in some parts of Europe these wage data go all the way back to the 13th century and so what the historians looking at the wage data have been able to suggest that the black death to by definition it transforms the land labour ratio at two of the three basic inputs in an economy land labor and capital black death transforms the land labour ratio by just killing a lot of people so there's now a lot more land available relative to the size of the population relative the labor force available labor and the demand for labor increases sharply what we should expect from that is a real wages will increase sharply and some that is exactly what happens I'm now going to show you one of my favorite graphs what we we serious people like to call a spaghetti graph with many many lines I'll show you a simple version of this in just a moment but the reason I put this one up is it in spite of all the lines going on each of the lines you can see the key at the bottom represents a different town from 1300 to 1750 in spite of the proliferation of lines we see some pretty clear trends here but then I'm using this graph because of one particular line in it we seized over on the right from 1300 to about 1450 basically wages are going up pretty much everywhere during the period immediately after the black death then from about 1450 1500 down to about 1600 so wages are falling almost everywhere as population grows and the land labour ratio generally shifts against labour then after 60 hundred other stuff starts happening I'll come back to in just a second about what's going on the right hand side of the graph basically we see there's up then down with the wages and we see it all across Europe it's not just in Western Europe that this happens and the as you can see from the key the bottom right in the key the black blob with the dotted lines is Krakow in Poland the one town when this graph is drawn for in Eastern Europe for which wage severs have been put together and to save you from having to look at me for the whole lecture you can try to see if you can pick out the Krakow line and then the mass of spaghetti up there but basically it follows pretty much the same trends and as the other lines from Europe or in spite of the the different institutional political outcomes east to west of the Eldar the real wages seem to follow roughly the same trends and all over Europe when you look at later historical sources all over Europe they look back on the 15th centuries this golden age a time of Caixin al they often call in Western your cakes and ale when standards of living for ordinary people are higher they were going to see again until the 19th century period around 1450 really was a golden age for peasants insofar as peasants get a golden age and this is what it would look like now up till very recently Europe was pretty much the only place we could do this sort of stuff with the real wages that's beginning to change now and just um about three weeks ago an article was published for the first time giving us some middle-eastern data like this now I owe this reference actually to somebody many of you I'm sure will know um one of my colleagues at Stanford named Walter Scheib who is a Finley fellow here at Darwin College back in the 1990s and Walter drew my attention this article in the Journal of economic history giving us some data from Cairo and Baghdad and Istanbul as well and it's not a great data set it's full of holes and I think there's a lot of room to argue about what exactly it means but again we're looking at real wages that they see you there the higher you go and the scores on the vertical axis the better off you are dates along the bottom and the guys who published this graph suggests that the data from Cairo seen generally with the European pattern that we see rising real wages in the aftermath of the Black Death falling as population starts to to grow again later out in China we don't have any quantitative data at this point available but the qualitative evidence sounds very similar the 15th century Golden Age then things get harder and harder so the real wage data seem to suggest the plagues don't necessarily lead to collapse don't necessarily lead to collapse followed by revival either their attempt the need to a temporary respite for misery real wage data seem to suggest that things get better for ordinary people rapidly after a plague and then deteriorate as the population grows so we've got some very different theories knocking around all of them driven by the Black Death episodes very different theories knocking around over where the plagues caused economic collapses or what on earth they actually do so what I'd like to do with what remains of my time is certainly out Brenner Brenner but make it a broader comparison still and trying to look at other examples we know art of plagues and say you know can we draw some broader conclusions here my inspiration in doing this is a very now for almost 40 year-old a very well known but William and Neil's plagues and people's who I'm sure some of you will come across wonderful book if you haven't it's absolutely great book but he's tries to write a whole history of the interrelation of humanity in its plagues and is a pioneering piece of work and one of the things you learn from it Neil's book is there been a lot of plagues and we know quite a lot about some of them enough in fact that we can begin to do some comparative work and this of course raises the second definitional problem what what exactly do we count as a plague and if we limited just to things like the bubonic and pneumonic plague to the 14th century obviously that cuts out an awful lot of the comparisons I'm sure there are questions for which that we are useful limit but I don't think it's very useful for this one so I'm going to be talking about plagues just as big outbreaks of contagious diseases the lead to very high mortality which is a very very broad look definition um you can argue over how much mortality should you have to count as a plague seems to me if you got to 10% mortality on a fairly like it with the help receive aid but fairly large-scale you are dealing with a something that's worth calling a plague here the 14th century black deaths very much qualifies for half the population in Europe probably maybe as much as 10 percent of the global population killed in the 14th century possibly things I the h1n1 influenza after World War one and the AIDS epidemic possibly these should not be counted as plagues and of course we sometimes talk to them as plagues but when we do I think most people you are using the word somewhat metaphorically so it defines out some cases defines in others um possibly the most severe plague in history other than the black death and was one which i think is a very useful comparison going back to the second century AD the Antonine plague as it's called by people who study the roman empire and this is one we don't actually know for sure what it was there's nothing no DNA recovered so far connected to it but probably it's something to do with smallpox this breaks out the first we hear of it is in 161 ad on the northwest frontiers of the Han Chinese Empire in marked in yellow over on the right here five years later 166 we're here of what sounds like a very similar illness breaking out in northern Syria the the edge of the Roman Empire it's probably been communicated across the steppes by very horse-based nomads probably is fueled by the merging of these previously separate disease pools enormous mortality although there's great argument over what the numbers actually were but enormous mortality and both these ancient empires in the Roman Empire and we've got enough quantitative data that we can begin talking a little bit about its impact on real wages and my colleague Walter Shai doll again has suggested that real wages increased by about 20 percent in Egypt in the late second century AD probably as a result of this plague which is exactly what the economist would lead us to believe no Chinese data have been quantified but again the qualitative data suggests we're dealing with something a little bit similar the Antonine plague the second century plague has very different long-run effects from the black death in Europe the Antonine plague is unambiguously leads to collapse everywhere it shows up and these are their social development scores can read for the east blue for the West in the period from one a B through to about five hundred and um both areas were particularly the western end of your agency serious declines in Social development's scores across this period the Western score falls by about a quarter across these five hundred years and the eastern score by less about ten percent by 300 AD and then begins recovering so very different outcomes from from the black death another Great Plague starts in the Mediterranean world in 541 this is often called the Justinian it plague this kills maybe a third of the population of the Byzantine Empire something that sounds rather similar to it is raging in the early 7th century in China although it's hard to be sure it's exactly the same thing the qualitative evidence suggests that wages bounced up in the Byzantine Empire in the aftermath of this a most significant piece of evidence comes from a guy called Zhang the deacon John the Deacon is at a Christian Bishop living in Constantinople and John complains bitterly because he can't get his laundry done anymore the plague has killed all the laundry people in Constantinople and now to get your laundry done you have to pay a fortune and I mean this has seams that is strikingly unchristian attitude to take in the wake of mass mortality but this is what John talks about and this is only oh this is gives you a sense of the quality of the evidence as well this is about as good evidence as we're getting on wages in the the early Byzantine Empire but it sounds like it's only in Egypt where the data are relatively good again we get some kind of spike in wages in the seventh to eighth centuries the Middle Eastern historians who put together the graph I showed you a version of a second ago they suggest that maybe this indicates a similar kind of rise in wages in this in the eighth and ninth centuries in the aftermath of this plague I'm not entirely stur by that one I must say but the picture I've got a bit more mixed with what what this plague does and particularly think this is true of the Social development's scores and the blue line again in the West the red line again the East dates across the bottom so after the 6th century AD Western social development continues tumbling Eastern social development though is rising and relatively rapidly and in fact the falling development in the West between about 100 and 780 this is the biggest sustained fall on record that I'm aware of in history Falls by like 34% across this period then this is a terrible social collapse there's lots of other plagues we can look at or you're all of them adds add more details more variation in the outcomes the famous plague that rage in Athens in 430 BC which the DNA suggests was typhoid fever this may have killed a quarter of the population but has a completely different set of results and the the Columbian Exchange when Europeans go to the Americas in the 16th century again a cocktail of diseases that is inflicted on the native population smallpox again seems to be a big part of this great debate over just how many people died a lot of recent work has suggested the mortality rate was actually something like 90% the DNA evidence suggests it was actually more like 50% there's still absolutely massive kill off the effects different again and the Americas get incorporated into a European dominated economy and social development on the whole rises but it was very very different things are going on III could go on at even more like throughout all the different planes we know about all the different things happening basic picture though is um there's lots of different outcomes in economic terms with different plagues different times and places it's easy as I sort of trying to put this talk together I realize it's easy to just degenerate into a laundry list here horrible plagues and the things they did to people and clearly the outcomes depend on the specifics of the case and exactly what else was going on but having said that I think it is useful to think a little bit about some patterns that we see here and how a social system responds to a Great Plague depends very much on the details I think of what else is happening and so I'm gonna just a minute or two compare what happens with the Black Death with what happens with the ancient Roman Antonine plague in the second century so I think the comparison is a little bit revealing and with the Black Death like I said the big outcome seems to be this decline and development is collapse followed by a much bigger surge in development and the size of the economy after 1400 the European labor markets respond in just the way mouths have said they should the wages rise the 14th century decline in the 15th and 16th this population is growing but then as I said is going to come back to the right-hand side of this spaghetti graph something rather interesting starts to happen you see over the right hand side of the graph the DH is this mass of coils of spaghetti starts to separate out into two trends after about 1600 ad 1650 ad and a small a small group of northwest European cities see sustained increases of standards of living for ordinary people whereas the cities of southern Europe and Eastern Europe generally see declining slower but still declining standards of living across the 17th and 18th century so this is bifurcation is beginning in Europe at this period even though population continues to grow in northwest Europe grows that very fast and the wages are behaving in non Malthusian ways there's enormous arguments about why this is happening economic historians get very passionate about this my own feeling is that what really drives this divergence is the creation of a new kind of economy around the Atlantic Ocean as technologies developed to the point the Atlantic can be mastered and brought within an economic system and wealth starts to flow into Northwest Europe the Europeans create what also he's going to show you there this is a simplified version of the graph should have put this up first where you can see this divergence a lot more clearly here and the divergence is driven by wealth flowing into northwest Europe by the creation of what historians like to call triangular trades in the Atlantic Ocean where the the ocean is big enough that there are very different societies and Ecology's around it but small enough that you can zip around in ships and buying and selling different things at different points generating profits everywhere you stop creating wealth on a scale that the world has never seen before and Northwest Europeans are relative late comers to to this Atlantic economy the Spaniards have already got all the good bits of the new world all the gold and silver is the Europeans are forced to try to make money in different ways and the Northwest Europeans are the ones who discover the possibilities of integrating the Atlantic the shores of the Atlantic into a single gigantic economy they they develop and dominate this triangular trade so European wages generally fall after 1500 or in 1450 as population grows but then by 1600 in northwest Europe wages are going up again as this Atlantic economy absolutely booms and more and more Europeans are drawn into a labor market selling their labor path and it's ever been the case before historians often talk about an industrious revolution as opposed to an industrial revolution in this period as people are working more and more and the European economy is booming now nothing like that happened in the aftermath of the second century AD Antonine plague where we get much more sustained long-term economic decline 700 year decline really Agana we probably see labor markets responding to playing in a very Malthusian way of rising wages followed by falling wages as a population recovers again we see something rather like what happens after the Black Death with the changing meaning of geography after the Black Death the Atlantic has changed from being a barrier into being this great economic highway and the geography that changes during the period of the Antonine plague azar very very diff with very different consequences this time the part of the world that seems to change its meaning is the steps through the great band of grasslands stretching from Manchuria to Hungary perfect horse breeding territory once you've got big horses perfect territory for riding around a lot moving from waterhole to waterhole great place for people to build up large numbers of cavalry to raid and steal stuff from empires other the band of Empires who stretches in China to the Mediterranean um during this period the steppes go from being this barrier to the north of the the great band of Empires across the old world they go forming a barrier to being a sort of highway but the only people who can use this highway are people with well-developed forces of cavalry very large reliance on horses and what happens is that from about 200 AD through to about 1400 the great empires from the Mediterranean to China never really get military domination over the steps they're always vulnerable to invasions from the steppes which fill the literature of the period here are just some shots of some randomly selected Mongol pictures Mongols devastating everything in their path over and over again great empires are overthrown by invasions from the steppes in fact the general picture that we get of the stability of states across this period here's another spaghetti graph looking at great empires of different regions Europe the Middle East China and India from the o1 ad to 1400 the area of the largest states in each region expressed in millions of squared kilometers on the vertical axis the purple line or you sees a median - median regression line - the sizes of these empires basically the steady decline the size of empires across this period as the steppes become more and more of a superhighway for nomadic bandits great empires are never able to re-establish themselves after the Antonine collapse sets in they are never able to recreate great economic systems that quite rival the Roman one or at least not until about the 12th century when Song Dynasty China - something comparable although it never really exceeds what the Romans now this cycle of economic chaos and breakdown this gets broken around the Year 1400 by two developments I'm not the kind of things that you might expect to break a downward economic cycle but the two big developments ironically they are pioneered in China but then really exploited and perfected in Europe the two developments are ocean-going ships and guns and what you see the top left is a modern reproduction of the 15th century Chinese junk this vessel could have sailed absolutely anywhere in the world if it had chosen to do so bottom right is the oldest known true gun in the world found on the battlefield in Manchuria by true gun I mean a gun we're gonna powder explodes violently enough to propel a projectile out of the tube and kill somebody on the other end of it all this known true gun in the world about 1288 found in Manchuria here we've got the European versions and much adapted naval and maritime technology you see in one replica of one of Columbus's ships from the end of the 15th century bottom right the oldest European representation of the gun this was painted on the office a manuscript in Oxford in 1329 this is 41 years after the world's first known gun appears no invention in the history of the world had ever spread as fast as the gun which is one of the reasons why I think gun control in America is doomed not to succeed everybody loves guns now this package once it was put in place together and basically Asians used guns to close the step highway down Europeans use ships and guns to open up the oceans and turn the Atlantic into a highway and this I think accounts for the differences in the outcomes after the Black Death and the the Antonine plague centuries earlier now lots and lots of more comparisons are possible lots more lessons we could try to draw out of this but I think a couple of conclusions emerge one of the things historians have a bad reputation for is always adding more complexity in more details muddying the patterns more more I think often there with comparative history what happens like in a lot of fields you start off with very simple pictures when you know almost nothing you've only got two data points you can always join in with a straight line you know almost nothing the story is simple you learn more and more it becomes a complete mess you don't know anything you get to a certain point though where you've got enough data you do begin to see some big patterns emerging I think we can do this with the the historical comparison that plagues so a couple of things I think we can say after you're looking at a variety of historical cases and the first of them is that by definition if a plague is something that kills a lot of people by definition plagues shift the land labour ratio in favor of the laborers this drives up wages weakens the positions of employers and landlords leads to something of a golden age for ordinary people in the aftermath of the plagues but relatively quickly the balance will shift back again as the population recovers and it seems to vary how long it takes but typically only three generations seems to be a good ballpark figure the way how long it'll take to get you back to where you were before the plague is struck and this I think is a valid generalization that can be applied to pretty much all of these cases and the exception that proves the rule I think is Northwest Europe after 1600 where we see that what makes the European experience so different and leads to this Cecilie sustained recovery and rather than as a return to where things have been before is that population is expanding but markets and productivity are expanding even faster and that I think is what makes the big difference markets and productivity grow faster than population and that makes a big change the Industrial Revolution then accelerates this growth even more changes things even further so there are things that the first generalization second a point I think we can draw out all these these playing stories is that the plagues don't directly cause economic collapse they're a shock to a system and people have got ways of doing things a plague dramatically shocks it and shakes it up and in the wrong circumstances by which I mean basically when the plague comes as part of this bundle of five horsemen of the apocalypse and the wrong sir Constance's plagues can be a major factor leading toward economic and social collapse and this is what we see of course in the second century AD and after what we see with the Justinian plague of the 6th or 7th centuries so ok what can we learn to wrap up what can we learn from this long term comparative history can its make any useful suggestions for us about where things might be going in the 21st century and I think maybe it can at least in in broad terms I think you're clearly I guess if you've been coming to these plague lectures you will have heard a lot about this already about the likelihood of plagues in the 21st century it seems to me fairly clear we are at great risk of major epidemic diseases spreading rapidly around the world this is I mean nobody can say whether this is going to happen on a major scale but the risk of it happening is enormous and the speed of transportation I think is young obviously one of the major things it's made the risks so much higher that it's tended to be in the past and it's very easy to document something this bad by looking across the history of 20th century your massive epidemic diseases and the h1n1 influenza that I mentioned earlier and locality and the first world war in 1918 there's debates about how exactly this got started what spreaded but clearly there the movements are very very large numbers of young men back and forth across the Atlantic is one of the big things I killed probably 50 million people in 1918 to 1919 probably a little bit of debate but it probably broke out in US army camps in France originally probably involved disease jumping from pigs and kept at the camp to humans and then it spread among the humans spreads across the entire planet is just devastating and then it burns itself out and relatively quickly the AIDS virus I mean a AIDS seems to have been incubating in Africa's as at least about 1959 and maybe even earlier than that I'm not spreading all that much though not a lot of mobility taking it out of Africa and then in the 1980s it abruptly spreads across four countenance SARS SARS is identified in 2003 in the space of 37 it's identified in 37 countries within within the first few weeks of the first cases and being identified in East Asia dramatic increase in the speed and scale at which these diseases are spreading of course the other side of the same coin is as a dramatic increase in the speed of our ability to respond to these diseases back with the h1n1 virus in 1918 and there was not a lot that could be done about this so there's more that could be done could be done with any earlier plague but not a lot could be done in 1918 and with AIDS HIV genome gets sequence after about 15 years they figure out what the actual genome is with SARS that sequence in 31 days so you're just a spectacular increase in the speed of our ability to respond because we don't know if we will carry on winning the race against these diseases in the 21st century and and whether we do or not the 21st century plague is going to be pretty horrendous and that with the World Health Organization estimates that if a new influenza version which of course they were evolving constantly and if a new version were to tudi breakouts and if it were to behave pink excuse me like the h2n2 virus that broke out in 1957 which is a relatively mild version of flu that killed one to two million people in 1957 a new version if it behaved like that would kill between two and seven point four million people if it behaved like the 1918 h1n1 virus it would kill something like 200 million people so that other scary statistic and the World Bank estimates that a pandemic they're a little vague about what they mean exactly by pandemic they estimate there would knock five percent of world GDP a lot of people think that's actually a very conservative estimate and the World Health Organization has a really cheery page on its website which of calls the ten things you need to know about pandemic influenza and I'm not going to give you all ten of them but just pick that my five favorite things you need to know about pandemic influenza it says the oh I'm going to show you another one of my gruesome disease pictures though the world may be on the brink of another pandemic all countries will be affected medical supplies will be inadequate large numbers of deaths will occur economic and social disruption will be great so that's you know just five out of ten things to look forward to how bad can it get it can get pretty bad a few years ago we had this conference at Stanford called a world at risk and they're all these very very big name people speaking this conference or secretaries of state and defense and health ministers from around the world and and basically they started our we started breakfast with people talking I think that was about nuclear proliferation losing control of weapons of mass destruction as the day goes on we go into more and more disastrous topics and the epidemic comes in the afternoon but the Sun was going down as this guy was talking about the epidemic you can see the entire room everyone just wanted to kill themselves now get it get it over with how bad can it get it can get very very bad and I think one of the things people particularly seem to worry about is the breakdown of supply chains that especially the food supply chain did if we are dealing with an epidemic that kills 200 million people say I mean we're gonna have millions of people dying millions of more people feeling terrible and then many many many millions staying away from work because they don't want us to breathe our disgusting germs on them I will likely to have a complete collapse of the global food supply and hundreds of millions of people starving so this is a really really awful scenario because I'm coming to the end how go ahead increasingly depressing notes as we come near the end of the talk well a 21st century plague leads to an economic collapse on the scale of some of these ones that we've seen earlier well I think long term history the kind I do it tells you what to look for but it doesn't actually tell you the answers there's no way to learn the answers from the past but you can at least I think get a sense of what problems we should be worrying about and look and and like I was saying one of the big things we learn from comparing the post black death northwest Europe with post Antonine plague Roman Empire is that what makes the Black Death a relatively pleasant experience for Europe bizarre way to put it but you know what makes it so that the the rebound is so big in Europe is that the economy grows faster than the population in Europe bath in northwest Europe after 1600 whereas that doesn't happen back in the Roman Empire now I think there are some reasons to think that in the 21st century that could well happened that our economies could grow faster than a population recovery in the aftermath of a major pandemic but that equation there that up the debate among the experts on this I think there's actually a much more immediate problem for a 21st century plague which is one that was never faced by anybody before and trying to deal with the plague um the the horsemen of the apocalypse as I emphasized one of the big things that goes on in when you get there these five forces coming together it's state failure and a great spike in violence and wars being fought back in the second century or the 14th century when people wanted to fight their Wars they had bows and arrows and they could kill a lot of people with bows and arrows we however have these and these really kill a lot of people in the past every great social and economic collapse has been accompanied by a massive spike in violence so it's not insane to suggest that if we were to see a great collapse of 21st century one of the things it would lead to it was large-scale nuclear war now this is something I've spent a lot of time thinking about lately not all together happen but a lot of time thinking about this lately and I've got a new book coming out about one last advertising opportunity out in just a few weeks out on April Fool's Day which my publisher insists is a coincidence and looking at the long term history of war and thank you very much about the this a potential future that's ahead of us now back in the mid 1980s um various groups of Defense concern in the u.s. were hired on to run war games to try to figure out what are the likely death tolls if we have major nuclear war and the first group that's hired on ran its war game came back with a conclusion that out of the six billion or so people in the world at that point we can expect 1 billion to be dead after the first week and then unpredictable numbers of secondary deaths from hunger disease everything else that follows in its wake and Department of Defense really didn't like that prediction so they hire another group who run their war game come up with almost exactly the same results and the third and the fourth on it goes everybody comes to the same conclusion at least a billion dead in the first week or so now the bad news we have vastly more powerful weapons available now than we did then here's just a small selection of them the b-2 bomber that you see down the bottom and that can carry a 10 Megaton nuclear load that is 750 Hiroshima Zhan 1 aircraft so this this is serious it's a scary we have we have robot aircraft that can land and take off on aircraft carriers at sea with no humans being involved at all this is you know order what multiple orders of magnitude increase in destructive power over what we had in World War two good news though the good news is that for every 20 nuclear warheads in the world in 1986 there is now one and the number continues to fall we actually could not kill everybody in the world in the first couple of weeks it would take us weeks and weeks to build all the bombs we needed to do that so this is this is pretty good news we can't kill everyone at once anymore but I want to close though actually I despite of all this stuff I want to close on a happy note the big thing I felt I learned writing this book about war was that the story they the sort of I think little recognized happy story of the last 10,000 years is the growing human mastery of violence and I realized it's hard to recognize this when you're hearing news from Ukraine and Syria and all these other terrible things going on but basically across the last 10,000 years rates of violent death have plunged and this is one of the graphs you use in my new book if you lived in a Stone Age society probably you're facing a ten to twenty percent risk of dying violently in the early 21st century globally you're facing something like a 0.7 percent risk of dying violently if you live in Denmark your risk of dying violently is one in a hundred and eleven thousands this is good this is a good trend and I suggest in this new book that there are actually good reasons to think this is going to continue that we are mastering the use of violence and perhaps if we do have a new great epidemic in the 21st century it won't end in the worst case scenario which is nuclear war so ok to conclude let's go on to end with a typically depressing plague picture after all due plagues cause economic collapse I think the answer has to be no although they can contribute under the wrong circumstances there's a serious risk of a great new plague in the 21st century I suspect them not a serious risk of a major collapse of the kind that's been seen over and over again in the past with plagues and that at least is some good news so thank you very much for listening [Applause] thank you so what can I say Ian thank you for a fascinating overview of how different communities were affected have been affected by plagues and the much longer-term consequences of those plagues which I guess normally we attend to ignore just focus on the on the immediate death and loss of population I mean we've had an awful lot of doom and gloom in this lecture series and today it's absolutely no exception and I just think back to last week we know we should be really worried about the global population growing too fast to you know go getting up to ten billion at the other extreme we hear here that if the population increases rapidly after a plague that will facilitate economic recovery I mean the happy medium in all of this is obviously almost impossible to achieve so we have to hope that our societies human societies are really ingenious and able to respond quickly to problems so next week the 2014 Darwin college lectures conclude with dr. Rowan Williams from maudlin college here in Cambridge who's going to talk about plagues and metaphor but Ian you've given us a very important message we can take comfort that plagues are don't always results in major economic and social collapse it could be worse the answer as you said at the beginning is sometimes not always so let's hope that sometimes really is the outcome for our generations thank you very much indeed you [Music] [Applause]

Channel: Darwin College Lecture Series

Views: 7,711

Keywords: Plagues, Darwin College, Darwin College Lectures, University of Cambridge, Professor Ian Morris, Stanford University, Plagues and economic collapse, economic collapse, black death, Professor of Classics

Id: CzVZi7xjJYY

Length: 59min 23sec (3563 seconds)

Published: Sun Feb 23 2020