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Cliodynamics is a transdisciplinary area of research integrating historical macrosociology, cultural and social evolution, economic history/cliometrics, mathematical modeling of long-term social processes, and the construction and analysis of historical databases. Cliodynamics: The Journal of Quantitative History and Cultural Evolution is an international, peer-reviewed, open-access journal that publishes original articles advancing the state of theoretical knowledge in this transdisciplinary area. In the broadest sense, this theoretical knowledge includes general principles that explain the functioning, dynamics, and evolution of historical societies and specific models, usually formulated as mathematical equations or computer algorithms. Cliodynamics also has empirical content that deals with discovering general historical patterns, determining empirical adequacy of key assumptions made by models, and testing theoretical predictions with data from actual historical societies. A mature, or ‘developed theory’ thus integrates models with data; the main goal of Cliodynamics is to facilitate progress towards such theory in history and cultural evolution.

This journal is available for sharing and reuse under a Creative Commons Attribution (CC BY) 4.0 International License which means that all content is freely available without charge to users and their institutions. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles in this journal without asking prior permission from the publisher or the author.

Cliodynamics is a member of the Directory of Open Access Journals (DOAJ) and Scopus


The Growth and Decline of the Western Roman Empire: Quantifying the Dynamics of Army Size, Territory, and Coinage

We model the Western Roman Empire from 500 BCE to 500 CE, aiming to understand the interdependent dynamics of army size, conquered territory and the production and debasement of coins within the empire. The relationships are represented through feedback relationships and modelled mathematically via a dynamical system, specified as a set of ordinary differential equations. We analyze the stability of a subsystem and determine that it is neutrally stable. Based on this, we find that to prevent decline, the optimal policy was to stop debasement and reduce the army size and territory during the rule of Marcus Aurelius. Given the nature of the stability of the system and the kind of policies necessary to prevent decline, we argue that a high degree of centralized control was necessary, in line with basic tenets of structural-demographic theory.


This article was updated on 01/09/2020 to correct an error in equation (3.5). Page numbers were updated on 01/05/2021.

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Assessing Simulations of Imperial Dynamics and Conflict in the Ancient World

The development of models to capture large-scale dynamics in human history is one of the core contributions of cliodynamics. Most often, these models are assessed by their predictive capability on some macro-scale and aggregated measure and compared to manually curated historical data. In this report, we consider the model from Turchin et al. (2013), where the evaluation is done on the prediction of “imperial density”: the relative frequency with which a geographical area belonged to large-scale polities over a certain time window. We implement the model and release both code and data for reproducibility. We then assess its behavior against three historical datasets: the relative size of simulated polities versus historical ones; the spatial correlation of simulated imperial density with historical population density; and the spatial correlation of simulated conflict versus historical conflict. At the global level, we show good agreement with population density (R2<0.75), and some agreement with historical conflict in Europe (R2<0.42). The model instead fails to reproduce the historical shape of individual polities. Finally, we tweak the model to behave greedily by having polities preferentially attacking weaker neighbors. Results significantly degrade, suggesting that random attacks are a key trait of the original model. We conclude by proposing a way forward by matching the probabilistic imperial strength from simulations to inferred networked communities from real settlement data.


Page numbers for this article were updated on 01/05/2021.

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Book Reviews

Deconstructing a Discipline. A Review of Taking Back Philosophy: A Multicultural Manifesto by Bryan Van Norden (Columbia University Press, 2017)

A review of Taking Back Philosophy: A Multicultural Manifesto by Bryan Van Norden (Columbia University Press, 2017).

Page numbers for this review were updated on 01/05/2021.