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. 2012;7(10):e48596.
doi: 10.1371/journal.pone.0048596. Epub 2012 Oct 31.

Global civil unrest: contagion, self-organization, and prediction

Dan Braha  1
Affiliations

Global civil unrest: contagion, self-organization, and prediction

Dan Braha. PLoS One. 2012.

Abstract

Civil unrest is a powerful form of collective human dynamics, which has led to major transitions of societies in modern history. The study of collective human dynamics, including collective aggression, has been the focus of much discussion in the context of modeling and identification of universal patterns of behavior. In contrast, the possibility that civil unrest activities, across countries and over long time periods, are governed by universal mechanisms has not been explored. Here, records of civil unrest of 170 countries during the period 1919-2008 are analyzed. It is demonstrated that the distributions of the number of unrest events per year are robustly reproduced by a nonlinear, spatially extended dynamical model, which reflects the spread of civil disorder between geographic regions connected through social and communication networks. The results also expose the similarity between global social instability and the dynamics of natural hazards and epidemics.

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Conflict of interest statement

Competing Interests: The author has declared that no competing interests exist.

Figures

Figure 1
Figure 1. Observed civil unrest event count distributions.
The incidence of civil unrest events per year is measured by summing over the reported country-level number of anti-government demonstrations, riots, and general strikes (see the section Domestic Conflict Data), for all countries within a particular subregion of the world (see the section Countries and Geographical Regions Included in the Study). The figure shows the log-log plot of the complementary cumulative distribution of civil unrest event count, formula image.(A) Unrest event count distributions for geographical subregions of Asia: Western Asia (○); South-Eastern Asia (□); Eastern Asia (▵); Southern Central Asia (▿). (B) Unrest event count distributions for geographical subregions of Africa: Western Africa (○); Southern Africa (□); Middle Africa (▵); Eastern Africa (▿). (C) Unrest event count distributions for geographical subregions of Europe: Western Europe (○); Southern Europe (□); Northern Europe (▵); Eastern Europe (▿). (D) Unrest event count distributions for geographical subregions of America: Caribbean, Central, and South America (○); North America (□).
Figure 2
Figure 2. Social unrest spatial contagion model.
The model is defined on a square grid of formula image sites, which represents the division of a country into urban clusters (see the section Parameter Estimation for details). Each site of the grid can be in one of three different states: empty (“white”), susceptible to social unrest (“red”), and involved in social unrest (“crowd”). Sites are one grid step apart if they are directly adjacent to each other in either the horizontal or vertical direction, or are connected through weak links (e.g., site E4 is connected to site F2). The weak links are formed by associating with each site, with probability formula image, a single link to a site selected uniformly at random from the grid. The grid is updated synchronously according to the following rules: at each time step, empty sites become susceptible with probability formula image, and susceptible sites become involved in social unrest with probability formula image. Unrest contagion occurs on a short time scale as follows. If a site is involved in social unrest (e.g., sites B2 and E4), the unrest activity spreads with probability formula image to susceptible sites that are one grid step apart (e.g., sites C2, B3, or D5), which in turn can lead (with probability formula image) to further instabilities of susceptible sites that are two grid steps apart, three grid steps apart, and so on. Each of the sites involved in social unrest during a time step contributes to the size of the unrest contagion.
Figure 3
Figure 3. Observed data and best-fit curves for civil unrest event count distributions.
Observed values are denoted by circles. Solid best-fit lines denote average distributions calculated from 500 realizations of the social unrest contagion model. The goodness of fit of the model relative to the empirically observed unrest event count distributions was determined by measuring the distance between the observed and simulated distributions. Here, the tail-weighted Kolmogorov–Smirnov (wKS) statistic is used (see the section Assessing the Goodness of Fit of the Model). The fit of the model is very good for all regions. Goodness-of-fit (wKS) and fitted parameters formula image for all regions: Western Asia = 0.1269 formula image, South-Eastern Asia = 0.1581 formula image, Eastern Asia = 0.1492 formula image, Southern Central Asia = 0.1078 formula image, Western Africa = 0.1749 formula image, Southern Africa = 0.2513 formula image, Middle Africa = 0.1856 formula image, Eastern Africa = 0.1191 formula image, Western Europe = 0.1436 formula image, Southern Europe = 0.11220 formula image, Northern Europe = 0.16 formula image, Eastern Europe = 0.1634 formula image, Caribbean, Central, and South America = 0.0707 formula image, North America = 0.2349 formula image. Values of wKS that are less than 0.3 represent good fits (see the section Assessing the Goodness of Fit of the Model).
Figure 4
Figure 4. Calculated size of the grid over time based on an average urban cluster of 26250 people.
Figure 5
Figure 5. Goodness-of-fit (average wKS statistics) and simulated event count distributions for various grid sizes.
Observed values for each sub-region of Asia are denoted by circles. Solid best-fit lines denote average distributions calculated from 500 realizations of the social unrest contagion model by using a grid size formula image. Simulated count distributions for grid sizes formula image use the fitted parameters obtained for formula image (see Fig. 3). Goodness-of-fit (wKS) for all regions and grid sizes: Western Asia: 0.1269 formula image, 0.1254 formula image, 0.1265 formula image; South-Eastern Asia: 0.1581 formula image, 0.1682 formula image, 0.1692 formula image; Eastern Asia: 0.1492 formula image, 0.1521 formula image, 0.1598 formula image; Southern Central Asia: 0.1078 formula image, 0.1161 formula image, 0.1199 formula image. The differences between the curves are too small to be visually noticeable. Running time on an Intel i7 Core processor was approximately 6.6 hours formula image, 21 hours formula image, 50.56 hours formula image.
Figure 6
Figure 6. Effect of mass media on civil unrest activity.
(A) Change in the total number of radios, television receivers, and phones, owned or operated per capita: 1919 to 2008. Widespread use of telecommunication technologies started around 1950. (B) The empirically observed distributions of the number of unrest incidents in the world: for the entire period of 1919–2008, and for pre- and post-1950.
Figure 7
Figure 7. Effect of network structure on civil unrest activity.
Observed values for each sub-region of Asia are denoted by red circles. Black points denote best-fit average distributions calculated from 500 realizations of the social unrest contagion model by using a grid size formula image and a uniform distribution of long-range links (fitted parameters formula image for all regions are given in Figure 3). In all cases, a scale-free overlay network was generated with roughly the same number of directed links, formula image, as in the corresponding uniform overlay network. Here, formula image is the expected number of long-range links on a square grid of formula image sites when the uniform distribution is used.
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References

    1. Perrot M (1987) Workers on strike: France, 1871–1890. New Haven: Yale University Press. 321 p.
    1. Moore B (1978) Injustice: The social bases of obedience and revolt. New York: White Plains. 540 p.
    1. Polletta F (1998) “It was like a fever …” narrative and identity in social protest. Social Problems 45: 137–159.
    1. Biggs M (2005) Strikes as forest fires: Chicago and Paris in the late nineteenth century. Am J Sociol 110: 1684–1714.
    1. Scarman LG (1981) Scarman report: The Brixton disorders. London: Penguin Book. 272 p.