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A web page by Peter Turchin
What is cliodynamics?
Many historical processes are dynamic. Empires rise and fall, populations and economies boom and bust, world religions spread or wither. Cliodynamics (from Clio, the muse of history, and dynamics, the study of temporally varying processes) is the new scientific discipline that investigates such dynamical processes in history.
Because nonlinear dynamical systems are capable of very complex behaviors (see the side bar), explicit mathematical models are a necessary ingredient in any research program for investigating them. We also need data describing how various aspects of the studied systems change with time. Fortunately, much quantitative empirical material on historical systems has been made available over the last couple of decades by workers in the field of cliometrics, and we can confidently expect that this process will continue in the future. The proposed general approach to investigating dynamical systems in history, therefore, is as follows. We start with verbal theories explaining historical change, either proposed by previous theorists, or formulated de novo. The verbal theories are translated into mathematical models, whose predictions can then be rigorously tested with cliometric data.
Historical Dynamics: Why States Rise and Fall published by Princeton University Press in December 2003
More details on the cliodynamics research program are given in my 2003 book Historical Dynamics. The book describes a systematic application of the general approach, sketched above, to the question of what mechanisms explain territorial expansion and contraction of states. Note that this is a technical book. Although I tried to present mathematical models and statistical techniques for testing hypotheses in as simple language as possible, if you don't have much experience with differential equations, certain parts of the book will require a substantial amount of work.
Click here for the prospectus and sample chapters of Historical Dynamics.
War and Peace and War: The Life Cycles of Imperial Nations published by Pi Press in September 2005 (the paperback version came out in February 2007)
War and Peace and War presents my ideas in a popular form. There is not a single equation in the text—but the more scientifically minded readers will miss such useful features as in-text citations. Still I suggest that even they read first the popular book, and then consult Historical Dynamics for the technical aspects of the approach.
The text of the introductory chapter here
Click here to see the book at amazon.com
Secular Cycles by Peter Turchin and Sergey Nefedov, in press at Princeton University Press (to be published in late 2008)
In Secular Cycles the Russian historian Sergey Nefedov and I have collaborated on presenting our best case study of cliodynamics. Our book focuses on grand—centuries-long—oscillations in demographic, economic, social, and political structures of historical agrarian societies. We start the book with an overview of the demographic-structural theory explaining secular cycles, but our main goal is the presentation of a large amount of empirical material documenting the trajectories of actual societies. Our survey includes chapters on England, France, and Russia from medieval to early modern periods, and the Roman Republic and Empire. Any and all comments will be extremely welcome.
Go to the Secular Cycles page
Recent Developments:
June 2007
Secular Cycles is done
We have completed the manuscript of Secular Cycles and sent it off to the publisher. We should be on track for getting it out by the end of 2008. The complete text (in PDF) is posted on the Secular Cycles page.
Go to the Secular Cycles page
May 2007
A Theory for the Formation of Large Agrarian Empires by Peter Turchin
Between 3000 BCE and 1800 CE there were at least 60 agrarian “megaempires” that controlled at the peak an area equal to or greater than one million of squared kilometers. What were the social forces that kept together such huge agrarian states? A clue is provided by the empirical observation that over 90 percent of megaempires originated at steppe frontiers—zones of interaction between nomadic pastorialists and settled agriculturalists. I propose a model for one route to megaempire. The model is motivated by the imperial dynamics in East Asia (more specifically, the interface between the settled farmers of East Asia and the nomads of Central Asia). It attempts to synthesize recent developments from theories of cultural evolution with insights from previous work by anthropologists on nomad/farmer interactions.
Posted as Working Paper 08-05-024 in the SFI series here
April 2007
Empirical regularities in historical dynamics: secular cycles by Peter Turchin (in Russian)
Article in press in the next issue of the almanac History and Mathematics.
The text is here
March 2007
Can History Become an Analytical, Predictive Science?
This is the paper that I presented at the meeting History, Big History, and Metahistory: An Approach through the Sciences of Complexity organized by the Santa Fe Institute in Honolulu, March 17-19, 2008
The text of the paper is here
December 2007
From Dec. 1, 2007 to May 31, 2008 I will be based at the Santa Fe Institute
This is my sabbatical year and I am spending six months of it at the SFI as Visiting Professor.
November 2007
My talk before general audience at Binghamton University on The Rise and Fall of Empires
There is a striking macrohistorical pattern: largest empires tend to arise at interfaces between settled and nomadic societies. An example of this pattern is the recurrent state formation in East Asia: China has been unified ~14 times throughout its history, and on all but one occasion the unification proceeded from North (and most frequently, Northwest). Simultaneously, a series of nomadic imperial confederations arose on the steppe side of the Inner Asian nomad/settled frontier. I will discuss one explanation for this empirical pattern. The basic idea is that the military power of mounted archers puts farming communities under selective pressure to unite to better resist the predation from the steppe. In turn, the nomads are forced to unite to be able to overcome the defenses of the emerging agrarian states. The scale of states on both sides of the steppe frontier increases in an autocatalytic fashion, until this runaway process is stopped by logistic and/or space limitations.
You can dowload the slides of the presentation (it's a big one - 40 MB!) here
October 2007
II International Conference Mathematical Modeling of Historical Processes: October 29-31, 2007; Institute of Applied Mathematics (Moscow)
Information on the conference (in Russian): here
The first degree in cliodynamics conferred: On October 10, 2008, at the Institute of History and Archaeology in Ekaterinburg Sergey Nefedov defended the D.Sc. (д.и.н.) thesis, entitled "Demographic-structural theory and its application to the study of socio-econoic history of Russia".
June 2007
A roundtable on History and Mathematics
On 25 June 2007 a group of 16 scholars, who included historians, anthropologists, philosophers, biologists, and mathematicians, gathered at the pansionat "Podlipki" near Moscow. For two days we brainstormed on the theme, is a science of history possible? And what needs to be done to accomplish it? As a result of this discussion, we formed the Cliodynamics Research Network that will coordinate our efforts in establishing and promoting theoretical and mathematical history. Our next planned activity is a general conference that will take place in late October at the Institute of Applied Mathematics in Moscow.
March 2007
Can history become a real science?
A talk presented on March 12 at the Santa Fe Institute. The slides in PowerPoint are here (13 MB)
Most historians and many philosophers believe that a science of history is impossible because history is too complex and historical processes are too different from physical or biological ones. Unlike molecules, for example, people have free wills. I will argue that, on the contrary, it is possible to employ regular scientific approaches in history. Certainly we can study large-scale dynamical processes in history, those that involve large collectives of people and unfold on the time scale of decades and centuries. We can build mathematical models for these processes and, more importantly, test model predictions with data. With just a little creativity it is possible to obtain quantitative time-series data on a wide variety of economic, social, and political aspects of historical systems. Furthermore, experience so far suggests that history is not simply a "mess," "one damn thing after another." There are strong patterns in time-series data. These recurring empirical regularities hint at the operation of some kind of laws of history (in the general sense of the term).
February 2007
The paperback version of War and Peace and War is out! See it at Amazon.com
Secular Cycles by Peter Turchin and Sergey Nefedov
Chapter 10 on the Romanov cycle in Russia is posted (go to the Secular Cycles page). Comments and critique are welcome.
Mathematics and history – my interview on Radio Liberty (in Russian)
Imperiów wzloty i upadki – czyli wojna, pokój i znów wojna a review by Piotr Tryjanowski in the Polish magazine "Nauka" (Science) read the text
January 2007
Commentary on my work in the American Conservative
Steve Sailer argues that multiculturalism doesn’t make vibrant communities but defensive ones. Go to the article
Secular Cycles by Peter Turchin and Sergey Nefedov
Chapter 9 on the Muscovite cycle in Russia is posted (go to the Secular Cycles page). Comments and critique are welcome.
November 2006
Two chapters came out in Hornborg, A (ed). World System History and Global Environmental Change (2007. Columbia University Press)
October 2006
Rat i Mir i Rat by Peter Turchin
A Serbo-Croatian translation of War and Peace and War has been published!
September 2006
Secular Cycles by Peter Turchin and Sergey Nefedov
Chapter 5 on the first early modern secular cycle in France is posted (go to the Secular Cycles page). Comments and critique are welcome.
July 2006
A review of Historical Dynamics in American Journal of Sociology by Dingxin Zhao
"... The book is well organized and clearly argued. ... unlike some simple-minded mathematical modelers, Turchin is very familiar with the relevant literature and has made a genuine effort to incorporate historical data into his models. I have learned a great deal from this work, and I strongly recommend it to scholars who are interested in historical sociology and mathematical modeling in social sciences. This said, however, I would like to point out some of the problems with this book..."
Secular Cycles by Peter Turchin and Sergey Nefedov
Chapter 4 on the medieval secular cycle in France is posted (go to the Secular Cycles page). Comments and critique are welcome.
June 2006
The New Scientist on Overconfidence in War, with my comments
Roxanne Khamsi reports on the recent study by Dominic Johnson (Princeton University) and colleagues go to the article (if not available on NewScientist.com, click here)
April 2006
Evolution of Cooperative Strategies from First Principles by Mikhail Burtsev and Peter Turchin published in the 20 April 2006 issue of Nature see the article in PDF
The commentary on our article on the German Radio (here)
March 2006
Secular Cycles by Peter Turchin and Sergey Nefedov
Chapters 2, 3, 6, 7, and 8 on secular cycles in England and Rome are posted (go to the Secular Cycles page). Comments and critique are welcome.
Commentary on my article in Structure and Dynamics
A comment by Andrey Korotayev
A critique by Natalia Komarova, and my response
Commentary on my work in the Russian magazine Politichesky Klass (The Political Class)
Nikolai Rozov discusses the implications of asabiya for modern Russian politics (see the text in Russian)
February 2006
A very nice review of cliodynamics in the French popular science magazine Sciences et Avenir. The PDF of the article (2.6 MB!) is here.
January 2006
Secular Cycles by Peter Turchin and Sergey Nefedov
A draft of Chapter 1: Introduction is posted (go to the Secular Cycles page). Comments and critique are welcome.
December 2005
A review of War and Peace and War in The Times Higher Education Supplement by Gordon Johnson
"History has had a long, and on the whole fruitful, relationship with adjacent subjects such as archaeology and anthropology, and is just emerging from a testing (and largely negative) cohabitation with literary and cultural theory. Turchin's view of our subject from the perspective of an evolutionary biologist, versed in the hard language of mathematics, promises a great deal. He may not have invented a new science or rewritten the history of the world, but he might encourage others in the history profession to think differently and to consider whether they should take down their disciplinary scaffolding from time to time to share their ideas more effectively with a popular readership."
Gordon Johnson is president of Wolfson College, Cambridge, and general editor, The New Cambridge History of India. full text of the review
November 2005
Evolution of Cooperative Strategies from First Principles by Mikhail Burtsev and Peter Turchin. To be published by Nature in early 2006
One of the greatest challenges in the modern biological and social sciences has been to understand the evolution of cooperative behavior. The main conceptual tool used in probing the logical coherence of proposed explanations has been game theory, including both analytical models and agent-based simulations. The game-theoretic approach yields clear-cut results, but assumes, as a rule, a simple structure of payoffs and a small set of possible strategies. We propose a more stringent test of the theory by developing a computer model with a significantly extended spectrum of possible strategies. In our model agents are endowed with a limited set of receptors, a set of elementary actions, and a neural net in between. Behavioral strategies are not predetermined; instead, the process of evolution constructs and reconstructs them from elementary actions. Two novel strategies of cooperative attack and defense emerged in simulations, as well as the well-known dove, hawk, and bourgeois strategies. Our results indicate that cooperative strategies can evolve even under such minimalist assumptions, provided that agents are capable of perceiving heritable external markers of other agents.
October 2005
A review of War and Peace and War in The New Scientist by Mark Buchanan
"Are there 'laws of history', patterns or regularities that would let us make predictions? Karl Marx thought he saw a steady progression in history, leading inevitably to a future of world government by the workers. British historian Arnold Toynbee saw cyclic patterns in the rise and fall of civilisations. But most historians today think that Marx and Toynbee were deluded, and that the pursuit of historical laws is, in general, a fool's errand. Refreshingly, Peter Turchin doesn't agree."
Mark Buchanan's latest book is Small World full text of the review
Another review of WPW in Library Journal text here
September 2005
Two articles published
Dynamical Feedbacks between Population Growth and Sociopolitical Instability in Agrarian States has been published by Structure and Dynamics go to the article
The most interesting result in this paper is that historical process can be studied with standard quantitative methods of natural sciences, such as time-series analysis, regression, and cross-validation. The statistical analysis reveals strong and repeatable patterns in the data on population numbers and the intensity of internal war. And history of science suggests that strong empirical regularities are usually associated with the action of fundamental laws...
A companion paper to Dynamical Feedbacks, A Primer on Statistical Analysis of Dynamical Systems in Historical Social Sciences (with a Particular Emphasis on Secular Cycles) was published in the same issue of Structure and Dynamics go to the article
Publicity associated with War and Peace and War: in TO BHMA (Greece), and Haaretz (Israel).
August 2005
Advance publicity for War and Peace and War
War and Peace and War is not yet out but is already getting press: in the August 25 issue of the Guardian, Empire of the Sums by Philip Ball. The article was also reprinted by the Sydney Morning Herald, which gave it a rather sensationalist title: The US Collapses: A Scenario. There is also a quick review in the Publishers Weekly (here it is).
May 2005
A review of Historical Dynamics in Contemporary Sociology by Philip A. Schrodt
"When an individual from the natural sciences takes on a complex issue in the social sciences, the result can be either an exercise in naIve determinism bordering on the absurd, or a set of provocative insights bringing new perspectives to classical problems. In the latest volume in Princeton's 'Studies in Complexity' series, biologist Peter Turchin has accomplished the latter..." see the whole review
Another review of Historical Dynamics in Theory and History by Noël Bonneuil
"...what he [Turchin] perceives to be insights gained by mathematical modeling could as easily be seen as misconceptions aided and abetted by mathematical dust in the eyes." see the whole review
December 2004
A review of Historical Dynamics in Economics of Transition by Paul Seabright
"This fascinating and ambitious book presents a number of attempts to quantify and test theories of the growth and decline of political organizations over a time-span of many centuries. The author’s ambition is to show that a rigourous quantitative theory of historical dynamics is possible—he calls it ‘cliodynamics’. This involves expressing the underlying relationships in the form of differential equations and testing predictions against various kinds of historical data. Though the underlying philosophy is a little less novel than the author recognizes—quantitative macroeconomics with political and institutional variables is becoming increasingly fashionable—the book is rich in applications of the approach and full of illuminating historical material..." see the whole review
A news article about Historical Dynamics in UConn Advance here
November 2004
East-West Orientation of Historical Empires by P. Turchin, J. M. Adams, and T. D. Hall
Does environment affect the ability of states to project power? If state expansion is more easily accomplished by staying within the same ecological zone, then state territories should be oriented in the east-west direction, mirroring the orientation of major ecological zones of the world. Our analysis of 62 largest empires in history supports this conjecture.
PDF of the article here
October 2004
Emergence of Cooperative Strategies from Elementary Actions in Agents with Neural Nets by Mikhail Burtsev and Peter Turchin
This article has now (October 2005) been accepted for publication by Nature (see above; the title has been changed to Evolution of Cooperative Strategies from First Principles)
PDF of the article here
May 2004
Dynamic maps of evolution of the state system and metaethnic frontiers in Europe during the two millenia CE
These slides complement the material in Chapter 5 of my book on Historical Dynamics, where I empirically test the predictions of the metaethnic frontier theory. The basic matrix is the snapshots of political landscape of Europe and Mediterranean taken at 100 year intervals from 0 to 1800 BCE. On top of the matrix I overlayed metaethnic frontiers. For European material see Appendix B of Historical Dynamics. Locations of Near Eastern frontiers are still in process of being worked out, and will probably be revised in future.
These PowerPoint slides were presented at the Santa Fe Institute working group on Analyzing Complex Macrosystems. PowerPoint presentation here (22 MB)
April 2004
Dynamical feedbacks between population growth and sociopolitical instability in agrarian states
Most preindustrial states experienced recurrent waves of political collapse and internal warfare. One possible explanation of this pattern, the demographic-structural theory, suggests that population growth leads to state instability and breakdown, which in turn causes population decline. Mathematical models incorporating this mechanism predict sustained oscillations in demographic and political dynamics. Here I test these theoretical predictions with time-series data on population dynamics and sociopolitical instability in early modern England, the Han and Tang China, and the Roman Empire. Results suggest that population and instability are dynamically interrelated as predicted by the theory.
A PDF of the article is here
This manuscript (rejected by Science last Fall) was the basis of my presentation at the Santa Fe Institute working group on Analyzing Complex Macrosystems.
Note added March 2005: the manuscript is now in press in Structure and Dynamics
February 2004
A review of Historical Dynamics in Nature by Joseph Tainter: here
"Social theory is a minefield, even for those experienced in it. The quantification of historical patterns is useful and important, and should have a place in historical research. But sophisticated mathematics will not improve naive social theories."
December 2003
Population Dynamics and Internal Warfare: a Reconsideration
by Peter Turchin and Andrey Korotayev
The hypothesis that population pressure causes increased warfare has been recently criticized on the empirical grounds. Both studies focusing on specific historical societies and analyses of cross-cultural data fail to find positive correlation between population density and incidence of warfare. In this paper we argue that such negative results do not falsify the population-warfare hypothesis. Population and warfare are dynamical variables, and if their interaction causes sustained oscillations, then we do not in general expect to find strong correlation between the two variables measured at the same time (that is, unlagged). We explore mathematically what the dynamical patterns of interaction between population and warfare (focusing on internal warfare) might be in both stateless and state societies. Next, we test the model predictions in several empirical case studies: early modern England, Han and Tang China, and the Roman Empire. . .
Article in press to appear in Social Evolution and History 5:2 (2006).
A PDF of the article is here
Supplementary Material (some details on data, analytical procedures) here
December 2003
Scientific Prediction in Historical Sociology: Ibn Khaldun meets Al Saud
One of the hallmarks of a mature discipline is its ability to make predictions that can be used to test scientific theories. Scientific predictions do not necessarily have to be concerned with future events; they can be made about what occurred in the past. I illustrate such retrospective prediction with a case study of conversion to Christianity in the Roman Empire. The bulk of the paper deals with the logic and methodology of setting up a scientific prediction in macrosociology. The specific case study I develop is the possible state collapse in Saudi Arabia. . .
A manuscript submitted to the American Journal of Sociology.
A PDF of the article is here The accompanying Excel spreadsheet: here
See it posted on QuanHist.Reccurrent Archive
Other publications:
Hall, Thomas D. and Peter Turchin. 2006. Lessons from Population Ecology for World-Systems Analyses of Long-Distance Synchrony. Chapter in: Hornborg, A (ed). World System History and Global Environmental Change. Columbia University Press, New York. PDF
Chase-Dunn, Christopher, Thomas D. Hall, and Peter Turchin. 2006. World-systems in the biogeosphere: urbanization, state formation and climate change since the Iron Age. Chapter in: Hornborg, A (ed). World System History and Global Environmental Change. Columbia University Press, New York.
Turchin, Peter and Thomas D. Hall. 2003. Spatial Synchrony among and within World-Systems: Insights from Theoretical Ecology. Journal of World-Systems Research 9:37-66. http://jwsr.ucr.edu/archive/vol9/number1/pdf/jwsr-v9n1-turchinhall.pdf
Turchin, P. 2003. Secular waves in historical demography (in Russian). Priroda 6: 3-12.
Peter Turchin's general web page (with CV, other publications, etc): here
This page was updated on March 28, 2006
The Wheel of Fortune
– an allegorical image of the cyclical nature of rise and fall of rulers, nations, empires, and civilizations.
One problem with it, however, is that it suggests a too mechanical view of historical dynamics... read more
REPRINTS AND PREPRINTS
Useful links:
Spatial Dynamics of Human Populations: Some Basic Models (a computer implementation of the asabiya-territory model in Chapter 4 of Historical Dynamics