arXiv subjects

Serge Galam

Publications and source records attributed to Serge Galam.

At least 55 records · Page 3Linked to original sources

arXiv2013

The Stabilizing Role of Global Alliances in the Dynamics of Coalition Forming

Coalition forming is investigated among countries, which are coupled with short range interactions, under the influence of external fields produced by the existence of global alliances. The model rests on the natural model of coalition forming inspired from Statistical Physics, where instabilities are a consequence of decentralized maximization of the individual benefits of actors within their long horizon of rationality as the ability to envision a way through intermediate loosing states, to a better configuration. The effects of those external incentives on the interactions between countries and the eventual stabilization of coalitions are studied. The results shed a new light on the understanding of the complex phenomena of stabilization and fragmentation in the coalition dynamics and on the possibility to design stable coalitions. In addition to the formal implementation of the model, the phenomena is illustrated through some historical cases of conflicts in Western Europe.

physics.soc-ph↗

arXiv2013

From Public Outrage to the Burst of Public Violence: An Epidemic-Like Model

This study extends classical models of spreading epidemics to describe the phenomenon of contagious public outrage, which eventually leads to the spread of violence following a disclosure of some unpopular political decisions and/or activity. Accordingly, a mathematical model is proposed to simulate from the start, the internal dynamics by which an external event is turned into internal violence within a population. Five kinds of agents are considered: "Upset" (U), "Violent" (V), "Sensitive" (S), "Immune" (I), and "Relaxed" (R), leading to a set of ordinary differential equations, which in turn yield the dynamics of spreading of each type of agents among the population. The process is stopped with the deactivation of the associated issue. Conditions coinciding with a twofold spreading of public violence are singled out. The results shed a new light to understand terror activity and provides some hint on how to curb the spreading of violence within population globally sensitive to specific world issues. Recent world violent events are discussed.

physics.soc-ph↗

arXiv2013

The drastic outcomes from voting alliances in three-party bottom-up democratic voting (1990 $\rightarrow$ 2013)

The drastic effect of local alliances in three-party competition is investigated in democratic hierarchical bottom-up voting. The results are obtained analytically using a model which extends a sociophysics frame introduced in 1986 \cite{psy} and 1990 \cite{lebo} to study two-party systems and the spontaneous formation of democratic dictatorship. It is worth stressing that the 1990 paper was published in the Journal of Statistical Physics, the first paper of its kind in the journal. It was shown how a minority in power can preserve its leadership using bottom-up democratic elections. However such a bias holds only down to some critical value of minimum support. The results were used latter to explain the sudden collapse of European communist parties in the nineties. The extension to three-party competition reveals the mechanisms by which a very small minority party can get a substantial representation at higher levels of the hierarchy when the other two competing parties are big. Additional surprising results are obtained, which enlighten the complexity of three-party democratic bottom-up voting. In particular, the unexpected outcomes of local voting alliances are singled out. Unbalanced democratic situations are exhibited with strong asymmetries between the actual bottom support of a party and its associated share of power at the top leadership. Subtle strategies are identified for a party to maximize its hold on the top leadership. The results are also valid to describe opinion dynamics with three competing opinions.

physics.soc-ph↗

arXiv2013

Applying a new method to the 2-d Ising transition

The Ising ferromagnetic model on a square lattice is revisited using the Galam Unifying Frame (GUF), set to investigate the dynamics of two-state variable systems within the frame of opinion dynamics. When combined with Metropolis dynamics, an unexpected intermediate "dis/order" phase is found with the coexistence of two attractors associated respectively to an ordered and a disordered phases. The basin of attraction of initial conditions for the disordered phase attractor starts from zero size at a first critical temperature $T_{c1}$ to embody the total landscape of initial conditions at a second critical temperature $T_{c2}$ with $T_{c1}\approx 1.59$ and $T_{c2}\approx 2.11$ in $J/k_B$ units. It appears that $T_{c2}$ is close to the Onsager result $T_{c}\approx 2.27$. The transition, which is first-order like, exhibits a vertical jump to the disorder phase at $T_{c2}$, reminiscent of the rather abrupt vanishing of the corresponding Onsager second order transition. However, using Glauber dynamics combined with GUF does not yield the intermediate phase and instead the expected single transition at $T_{c}\approx 3.09$. Accordingly, although the "dis/order" phase produced by the GUF - Metropolis combination is not physical, it is an intriguing result to be understood. In particular the fact that Glauber and Metropolis dynamics yield so different results using GUF needs an explanation. The possibility of extending GUF to larger clusters is discussed.

cond-mat.stat-mech↗

arXiv2012

Rational Instability in the Natural Coalition Forming

We are investigating a paradigm of instability in coalition forming among countries, which indeed is intrinsic to any collection of individual groups or other social aggregations. Coalitions among countries are formed by the respective attraction or repulsion caused by the historical bond propensities between the countries, which produced an intricate circuit of bilateral bonds. Contradictory associations into coalitions occur due to the independent evolution of the bonds. Those coalitions tend to be unstable and break down frequently. The model extends some features of the physical theory of Spin Glasses. Within the frame of this model, the instability is viewed as a consequence of decentralized maximization processes searching for the best coalition allocations. In contrast to the existing literature, a rational instability is found to result from forecast rationality of countries. Using a general theoretical framework allowing to analyze the countries' decision making in coalition forming, we feature a system where stability can eventually be achieved as a result of the maximization processes. We provide a formal implementation of the maximization principles and illustrate it in the multi-thread simulation of the coalition forming. The results shed a new light on the prospect of searches for the best coalition allocations in the networks of social, political or economical entities.

physics.soc-ph↗

arXiv2012

Modeling controversies in the press: the case of the abnormal bees' death

The controversy about the cause(s) of abnormal death of bee colonies in France is investigated through an extensive analysis of the french speaking press. A statistical analysis of textual data is first performed on the lexicon used by journalists to describe the facts and to present associated informations during the period 1998-2010. Three states are identified to explain the phenomenon. The first state asserts a unique cause, the second one focuses on multifactor causes and the third one states the absence of current proof. Assigning each article to one of the three states, we are able to follow the associated opinion dynamics among the journalists over 13 years. Then, we apply the Galam sequential probabilistic model of opinion dynamic to those data. Assuming journalists are either open mind or inflexible about their respective opinions, the results are reproduced precisely provided we account for a series of annual changes in the proportions of respective inflexibles. The results shed a new counter intuitive light on the various pressure supposed to apply on the journalists by either chemical industries or beekeepers and experts or politicians. The obtained dynamics of respective inflexibles shows the possible effect of lobbying, the inertia of the debate and the net advantage gained by the first whistleblowers.

physics.soc-ph↗

arXiv2012

The building up of individual inflexibility in opinion dynamics

Two models of opinion dynamics are entangled in order to build a more realistic model of inflexibility. The first one is the Galam Unifying Frame (GUF), which incorporates rational and inflexible agents, and the other one considers the combination of Continuous Opinions and Discrete Actions (CODA). While initially in GUF, inflexibility is a fixed given feature of an agent, it is now the result of an accumulation for a given agent who makes the same choice through repeated updates. Inflexibility thus emerges as an internal property of agents becoming a continuous function of the strength of its opinion. Therefore an agent can be more or less inflexible and can shift from inflexibility along one choice to inflexibility along the opposite choice. These individual dynamics of the building up and falling off of an agent inflexibility are driven by the successive local updates of the associated individual opinions. New results are obtained and discussed in terms of predicting outcomes of public debates.

physics.soc-ph↗

arXiv2011

Tailor Based Allocations for Multiple Authorship: a fractional $gh$-index

A quantitative modification to keep the number of published papers invariant under multiple authorship is suggested. In those cases, fractional allocations are attributed to each co-author with a summation equal to one. These allocations are tailored on the basis of each author contribution. It is denoted "Tailor Based Allocations (TBA)" for multiple authorship. Several protocols to TBA are suggested. The choice of a specific TBA may vary from one discipline to another. In addition, TBA is applied to the number of citations of a multiple author paper to have also this number conserved. Each author gets only a specific fraction of the total number of citations according to its fractional paper allocation. The equivalent of the h-index obtained by using TBA is denoted the gh-index. It yields values which differ drastically from those given by the h-index. The gh-index departs also from the `h-index recently proposed by Hirsh to account for multiple authorship. Contrary to the h-index, the gh-index is a function of the total number of citations of each paper. A highly cited paper allows a better allocation for all co-authors while a less cited paper contributes essentially to one or two of the co-authors. The scheme produces a substantial redistribution of the ranking of scientists in terms of quantitative records. A few illustrations are provided.

physics.soc-ph↗

arXiv2011

Market efficiency, anticipation and the formation of bubbles-crashes

A dynamical model is introduced for the formation of a bullish or bearish trends driving an asset price in a given market. Initially, each agent decides to buy or sell according to its personal opinion, which results from the combination of its own private information, the public information and its own analysis. It then adjusts such opinion through the market as it observes sequentially the behavior of a group of random selection of other agents. Its choice is then determined by a local majority rule including itself. Whenever the selected group is at a tie, i.e., it is undecided on what to do, the choice is determined by the local group belief with respect to the anticipated trend at that time. These local adjustments create a dynamic that leads the market price formation. In case of balanced anticipations the market is found to be efficient in being successful to make the "right price" to emerge from the sequential aggregation of all the local individual informations which all together contain the fundamental value. However, when a leading optimistic belief prevails, the same efficient market mechanisms are found to produce a bullish dynamic even though most agents have bearish private informations. The market yields then a wider and wider discrepancy between the fundamental value and the market value, which in turn creates a speculative bubble. Nevertheless, there exists a limit in the growing of the bubble where private opinions take over again and at once invert the trend, originating a sudden bearish trend. Moreover, in the case of a drastic shift in the collective expectations, a huge drop in price levels may also occur extremely fast and puts the market out of control, it is a market crash.

physics.soc-ph↗

arXiv2011

The formation of share market prices under heterogeneous beliefs and common knowledge

Financial economic models often assume that investors know (or agree on) the fundamental value of the shares of the firm, easing the passage from the individual to the collective dimension of the financial system generated by the Share Exchange over time. Our model relaxes that heroic assumption of one unique "true value" and deals with the formation of share market prices through the dynamic formation of individual and social opinions (or beliefs) based upon a fundamental signal of economic performance and position of the firm, the forecast revision by heterogeneous individual investors, and their social mood or sentiment about the ongoing state of the market pricing process. Market clearing price formation is then featured by individual and group dynamics that make its collective dimension irreducible to its individual level. This dynamic holistic approach can be applied to better understand the market exuberance generated by the Share Exchange over time.

physics.soc-ph↗

arXiv2010

Artifacts of opinion dynamics at one dimension

The dynamics of a one dimensional Ising spin system is investigated using three families of local update rules, the Galam majority rules, Glauber inflow influences and Sznadj outflow drives. Given an initial density p of up spins the probability to reach a final state with all spins up is calculated exactly for each choice. The various formulas are compared to a series of previous calculations obtained analytically using the Kirkwood approximation. They turn out to be identical. The apparent discrepancy with the Galam unifying frame is addressed. The difference in the results seems to stem directly from the implementation of the local update rule used to perform the associated numerical simulations. The findings lead to view the non stepwise exit probability as an artifact of the one dimensional finite size system with fixed spins. The suitability and the significance to perform numerical simulations to model social behavior without solid constraints is discussed and the question of what it means to have a mean field result in this context is addressed.

physics.soc-ph↗

arXiv2010

Collective beliefs and individual stubbornness in the dynamics of public debates

The combined effects of collective beliefs and individual stubbornness in the dynamic of a public debate are investigated using the Galam sequential probabilistic model of opinion dynamics. The study is focused on pair interactions for which the bias produced by collective beliefs is the decisive factor to win the debate. The current value of that bias is a fixed external parameter. It is a constant of the problem not given to change. In contrast, stubbornness is an individual property. It results from external ingredients, which are susceptible to be modified during the debate. More precisely, giving some beliefs we determine the required stubbornness to oppose its associated bias in the debate outcome. The results shed a new and counter intuitive light on paradoxical outcomes of sensitive issues, which are discussed in the public. The case of the global warming issue is discussed.

physics.soc-ph↗

arXiv2010

Public debates driven by incomplete scientific data: the cases of evolution theory, global warming and H1N1 pandemic influenza

Public debates driven by incomplete scientific data where nobody can claim absolute certainty, due to current state of scientific knowledge, are studied. The cases of evolution theory, global warming and H1N1 pandemic influenza are investigated. The first two are of controversial impact while the third is more neutral and resolved. To adopt a cautious balanced attitude based on clear but inconclusive data appears to be a lose-out strategy. In contrast overstating arguments with wrong claims which cannot be scientifically refuted appear to be necessary but not sufficient to eventually win a public debate. The underlying key mechanism of these puzzling and unfortunate conclusions are identified using the Galam sequential probabilistic model of opinion dynamics. It reveals that the existence of inflexible agents and their respective proportions are the instrumental parameters to determine the faith of incomplete scientific data public debates. Acting on one's own inflexible proportion modifies the topology of the flow diagram, which in turn can make irrelevant initial supports. On the contrary focusing on open-minded agents may be useless given some topologies. When the evidence is not as strong as claimed, the inflexibles rather than the data are found to drive the opinion of the population. The results shed a new but disturbing light on designing adequate strategies to win a public debate.

physics.pop-ph↗

arXiv2009

Ising model versus normal form game

The 2-spin Ising model in statistical mechanics and the 2x2 normal form game in game theory are compared. All configurations allowed by the second are recovered by the first when the only concern is about Nash equilibria. But it holds no longer when Pareto optimum condiderations are introduced like in the prisoner's dilemma. This gap can nevertheless be filled by adding a new coupling term to the Ising model, even if that term has up to now no physical meaning. An individual complete bilinear objective function is thus found to be sufficient to reproduce all possible configurations of a 2x2 game. Using this one-to-one mapping, new perspectives for future research in both fields can be envisioned.

physics.soc-ph↗

arXiv2008

Sociophysics and the Forming of Public Opinion: Threshold versus Non Threshold Dynamics

A two state model for opinion forming, which has proven heuristic power, is reviewed with a novel emphasis on the existence or absence of a threshold for the dynamics. Monitored by repeated small groups discussions floater agents update their opinion according to a local majority rule. A threshold makes the initial supports to flow towards eitheir one of two opposite attractors with only one single opinion. While odd sizes yield a threshold at fifty percent even sizes, which allow the inclusion of doubt at an opinion tie, produces a threshold shift toward either 0 or 1 giving rise to minority opinion spreading. Considering heterogeneous agents like contrarians and inflexibles turn the dynamics threshold less beyond sone critical values. One unique attractor at fifty-fifty drives then the dynamics. In addition inflexibles can generate asymmetry and if one sided they erase the threshold ensuring the associated opinion to eventually gain the all population support. It may shed a new and counter intuitive light on some social aspect of the global warming phenomenon.

physics.soc-ph↗

arXiv2008

Sociophysics: A review of Galam models

We review a series of models of sociophysics introduced by Galam and Galam et al in the last 25 years. The models are divided in five different classes, which deal respectively with democratic voting in bottom up hierarchical systems, decision making, fragmentation versus coalitions, terrorism and opinion dynamics. For each class the connexion to the original physical model and technics are outlined underlining both the similarities and the differences. Emphasis is put on the numerous novel and counterintuitive results obtained with respect to the associated social and political framework. Using these models several major real political events were successfully predicted including the victory of the French extreme right party in the 2000 first round of French presidential elections, the voting at fifty - fifty in several democratic countries (Germany, Italy, Mexico), and the victory of the no to the 2005 French referendum on the European constitution. The perspectives and the challenges to make sociophysics a predictive solid field of science are discussed.

physics.soc-ph↗

arXiv2008

Global Warming: the Sacrificial Temptation

The claimed unanimity of the scientific community about the human culpability for global warming is questioned. Up today there exists no scientific proof of human culpability. It is not the number of authors of a paper, which validates its scientific content. The use of probability to assert the degree of certainty with respect the global warming problem is shown to be misleading. The debate about global warming has taken on emotional tones driven by passion and irrationality while it should be a scientific debate. The degree of hostility used to mull any dissonance voice demonstrates that the current debate has acquired a quasi-religious nature. Scientists are behaving as priests in their will "to save the planet". We are facing a dangerous social phenomenon, which must be addressed from the social point of view. The current unanimity of citizens, scientists, journalists, intellectuals and politicians is intrinsically worrying. The calls to sacrifice our way of life to calm down the upset nature is an emotional ancestral reminiscence of archaic fears, which should be analyzed as such.

physics.soc-ph↗

arXiv2007

From 2000 Bush-Gore to 2006 Italian elections: Voting at fifty-fifty and the Contrarian Effect

A sociophysical model for opinion dynamics is shown to embody a series of recent western hung national votes all set at the unexpected and very improbable edge of a fifty-fifty score. It started with the Bush-Gore 2000 American presidential election, followed by the 2002 Stoiber-Schrőder, then the 2005 Schrőder-Merkel German elections, and finally the 2006 Prodi-Berlusconi Italian elections. In each case, the country was facing drastic choices, the running competing parties were advocating very different programs and millions of voters were involved. Moreover, polls were given a substantial margin for the predicted winner. While all these events were perceived as accidental and isolated, our model suggests that indeed they are deterministic and obey to one single universal phenomena associated to the effect of contrarian behavior on the dynamics of opinion forming. The not hung Bush-Kerry 2005 presidential election is shown to belong to the same universal frame. To conclude, the existence of contrarians hints at the repetition of hung elections in the near future.

physics.soc-ph↗