On Agent-Based Modelling of Large Scale Conflict Against a Central Authority

226 Pages·2016·6.11 MB·English

On Agent-Based Modelling of Large Scale
Conflict Against a Central Authority:
from Mechanisms to Complex Behaviour
A Thesis presented in partial fulfillment of the Requirements
for the Degree of Doctor of Philosophy in
Complexity Sciences
By
Carlos Miguel Reis Silva de Oliveira e Lemos
Thesis advisor: Professor Rui Jorge Lopes
Thesis co-advisor: Professor Helder Manuel Ferreira Coelho
December 2016

On Agent-Based Modelling of Large Scale
Conflict Against a Central Authority:
from Mechanisms to Complex Behaviour
Carlos Miguel Reis Silva de Oliveira e Lemos
Jury Members:
Doctor Ernesto Jorge F. Costa, Full Professor, University of Coimbra, Portugal
Doctor Helder Manuel F. Coelho, Full Professor, University of Lisbon, Portugal
Doctor Francisco C. Santos, Associate Professor, University of Lisbon, Portugal
Doctor Lu´ıs Antunes, Assistant Professor, University of Lisbon, Portugal
Doctor Rui J. Lopes, Assistant Professor, Instituto Universita´rio de Lisboa, Portugal
Doctor Pedro Magalh˜aes, Researcher, University of Lisbon, Portugal
President of the Jury:
Doctor Jorge Louc¸a˜, Assistant Professor, Instituto Universita´rio de Lisboa, Portugal
December, 2016

To my wife S˜ao and my daughters Mariana and Marta

Abstract
In this work, an Agent-Based model of large scale conflict against a central authority
was developed. The model proposed herein is an extension of Epstein’s Agent-Based
model of civil violence, in which new mechanisms such as deprivation-dependent
hardship, generalised vanishing of the risk perception (‘massive fear loss’) below a
critical ratio between deterrence and ‘group support’, legitimacy feedback, network
influences and ‘mass enthusiasm’ (contagion) were implemented. The model was
explored a set of computer experiments and the results compared with statistical
analyses of events in the “Arab Spring”.
The main contributions of the present work for understanding how mechanisms
of large scale conflict lead to complex behaviour were (i) a quantitative description
of the impact of the “Arab Spring” in several countries focused on complexity issues
such as peaceful vs violent, spontaneous vs organized, and patterns of size, duration
and recurrence of conflict events; (ii) the explanation of the relationship between the
estimated arrest probability and the size of rebellion peaks in Epstein’s model; (iii) a
new form of the estimated arrest probability with a mechanism of ‘massive fear loss’;
(iv) the derivation of a relationship between the legitimacy and action threshold for
complex solutions to occur with both low and high values of the legitimacy; (v) a
simple representation of political vs economic deprivation with a parameter which
controls the ‘sensitivity’ to value; (vi) the effect of legitimacy feedback; and (vii) the
effect of network influences on the stability of the solutions.
Keywords: Social Conflict, Complexity, Mechanisms, Agent-Based Model, Social
Simulation, “Arab Spring”
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Resumo
Neste trabalho, ´e apresentado um modelo baseado em agentes para o estudo do
conflito massivo contra uma autoridade central. O modelo proposto ´e uma extensa˜o
do modelo baseado em agentes para o estudo da violˆencia civil devido a Epstein,
incluindo os mecanismos de relac¸a˜o entre a privac¸a˜o relativa e ‘provac¸a˜o’ (hardship),
o desaparecimento generalizado da percepc¸a˜o de risco abaixo de uma relac¸a˜o cr´ıtica
entre a capacidade de dissuasa˜o e o ‘apoio colectivo’, a retroalimentac¸a˜o da legitimi-
dade em func¸a˜o da contestac¸a˜o, as influˆencias associadas as redes, e o mecanismo do
‘entusiasmo colectivo’ (conta´gio). O modelo foi explorado atrav´es de um conjunto de
experiˆencias de simula¸c˜ao, e os resultados comparados com uma an´alise estat´ıstica
´
de eventos ocorridos durante a “Primavera Arabe”.
Os principais contributos do presente trabalho foram (i) a descric¸a˜o quantitativa
´
do impacto da “Primavera Arabe” em diversos pa´ıses, focada em aspectos de complex-
idade; (ii) a explicac¸a˜o da relac¸a˜o entre a func¸a˜o de estimativa de probabilidade de
prisa˜o e a magnitude dos picos de revolta social; (iii) uma nova forma para a func¸a˜o
de estimativa de probabilidade de prisa˜o, como mecanismo de ‘perda generalizada do
medo’; (iv) a deduc¸a˜o de uma relac¸a˜o entre a legitimidade e o limiar de acc¸a˜o para a
ocorrˆencia de solu¸c˜oes com comportamento complexo, tanto para valores elevados
como baixos da legitimidade; (v) uma representa¸c˜ao simples da priva¸c˜ao pol´ıtica e
da privac¸a˜o econo´mica, com um paraˆmetro regulador da ‘sensibilidade’ ao valor; (vi)
a introduc¸a˜o do mecanismo de retroalimentac¸a˜o da legitimidade; e (vii) o efeito das
influˆencias devidas a redes na estabilidade das solu¸c˜oes.
Palavras-chave: Conflito Social, Complexidade, Mecanismos, Modelo Baseado
´
em Agentes, Simula¸ca˜o Social, “Primavera Arabe”
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Acknowledgements
I wish first of all to express my gratitude to my advisers, Professors Rui Jorge
Lopes and Helder Coelho, for their continuous advice and encouragement, as well
as for their personal support in some difficult moments during the long process of
preparing this thesis.
This work would hardly have been completed without the financial support of
the Portuguese Joint Command and Staff College (PJCSC). Thanks are due to
Lieutenant-General Xavier Matias of the Portuguese Army, who as Director of the
PJCSC always showed the highest consideration and enthusiasm towards my work
and gave high priority to funding my participation in several conferences to present
papers. Support by the BioISI - Instituto de Biossistemas e Ciˆencias Integrativas,
which provided the installations, working conditions and appropriate environment
for productive work, is also gratefully acknowledged.
Thanks are due to Professor Bruce Gilley of the Portland State University, for
sharing his data on legitimacy and presenting valuable explanations and suggestions
for modelling legitimacy feedback in the model developed in this work.
Finally, I thank my wife S˜ao and my daughters Mariana and Marta for their
continuous love, support, trust and enthusiasm, without which this work would have
never been completed. They were, are and will always be my strongest source of
energy and inspiration.