The present paper discusses implications for Agent-based Computational Economics (ACE) of a formal definition of emergence introduced by Dessalles, Phan in part I of this work. This exemplification is based on an extension of the model of emergence of classes by Axtell et al. The present paper...

The September 11 attack on the US has revealed an unprecedented terrorism worldwide range of destruction. Recently, it has been related to the percolation of worldwide spread passive supporters. This scheme puts the suppression of the percolation effect as the major strategic issue in the fight...

The September 11 attack on the US has revealed an unprecedented terrorism with worldwide range of destruction. It is argued to result from the first worldwide percolation of passive supporters. They are people sympathetic to the terrorism cause but without being involved with it. They just do...

The combined effects of collective beliefs and individual inflexibility in the dynamics 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...

A model for the dynamics of opinion forming in democratic public debate is presented. Using concepts and techniques from the physics of disorder the dynamics of social refusal spreading is studied within a perfect world, where the minority holds neither better arguments nor lobbying backing. The...

The effect of majority rule voting in hierarchical structures is studied using the basic concepts from real space renormalization group. It shows in particular that a huge majority can be self-eliminated while climbing up the hierarchy levels. This majority democratic self-elimination...

We discuss a cellular automata model to study the competition between an emergent better fitted species against an existing majority species. The model implements local fights among small group of individuals and a synchronous random walk on a 2D lattice. The faith of the system, i.e., the...

The recent astonishing wide adhesion of French people to the rumor claiming ‘No plane did crash on the Pentagon on September 11’, is given a generic explanation in terms of a model of minority opinion spreading. Using a majority rule reaction–diffusion dynamics, a rumor is shown to invade...

The concept and technics of real space renormalization group are applied to study majority rule voting in hierarchical structures. It is found that democratic voting can lead to totalitarianism by keeping in power a small minority. Conditions of this paradox are analyzed and singled out. Indeed...

The interplay between disorder and compressibility in Ising magnets is studied. Contrary to pure systems in which a weak compressibility drives the transition first order, we find from a renormalization group analysis that it has no effect on disordered systems which keep undergoing continuous...