Adjustment and social choice

We discuss the influence of information contagion on the dynamics of choices in social networks of heterogeneous buyers. Starting from an inhomogeneous cellular automata model of buyers dynamics, we show that when agents try to adjust their reservation price, the tatonement process does not converge to equilibrium at some intermediate market share and that large amplitude fluctuations are actually observed. When the tatonnement dynamics is slow with respect to the contagion dynamics, large periodic oscillations reminiscent of business cycles appear.Comment: 13 pages, 6 figure

Persistence of discrimination: revisiting Axtell, Epstein and Young

We reformulate an earlier model of the "Emergence of classes..." proposed by Axtell etal. using more elaborate cognitive processes allowing a statistical physics approach. The thorough analysis of the phase space and of the basins of attraction leads to a reconsideration of the previous social interpretations: our model predicts the reinforcement of discrimination biases and their long term stability rather than the emergence of classes.Comment: 21 pages, 7 figure

Bounded confidence and Social networks

In the so-called bounded confidence model proposed by Deffuant et al, agents can influence each other's opinion provided that opinions are already sufficiently close enough. We here discuss the influence of possible social networks topologies on the dynamics of this model.Comment: proceedings COSIN meeting Roma, 9/2003 sub. Eur. J. Phys

"Antiferromagnetism" in social relations and Bonabeau model

We here present a fixed agents version of an original model of the emergence of hierarchies among social agents first introduced by Bonabeau \textit{et al}. Having interactions occurring on a social network rather than among 'walkers' doesn't drastically alter the dynamics. But it makes social structures more stable and give a clearer picture of the social organisation in a `mixed' regime.Comment: 11 pages including 7 figure

Production networks and failure avalanches

Although standard economics textbooks are seldom interested in production networks, modern economies are more and more based upon suppliers/customers interactions. One can consider entire sectors of the economy as generalised supply chains. We will take this view in the present paper and study under which conditions local failures to produce or simply to deliver can result in avalanches of shortage and bankruptcies across the network. We will show that a large class of models exhibit scale free distributions of production and wealth among firms and that metastable regions of high production are highly localised

The Labour Market on the Hypercube

Positions offered on a labour market and workers preferences are here described by bit-strings representing individual traits. We study the co-evolution of workers and firm preferences modeled by such traits. Individual ”size-like” properties are controlled by binary encounters which outcome depends upon a recognition process. Depending upon the parameter set-up, mutual selection of workers and positions results in different types of attractors, either an exclusive niches regime or a competition regime.

Social Percolation and the Influence of Mass Media

Mass media shift the percolative phase transition observed in the marketing model of Solomon and Weisbuch.Comment: 6 pages including 4 figure

Heterogeneity and Increasing Returns May Drive Socio-Economic Transitions

There are clear benefits associated with a particular consumer choice for many current markets. For example, as we consider here, some products might carry environmental or `green' benefits. Some consumers might value these benefits while others do not. However, as evidenced by myriad failed attempts of environmental products to maintain even a niche market, such benefits do not necessarily outweigh the extra purchasing cost. The question we pose is, how can such an initially economically-disadvantaged green product evolve to hold the greater share of the market? We present a simple mathematical model for the dynamics of product competition in a heterogeneous consumer population. Our model preassigns a hierarchy to the products, which designates the consumer choice when prices are comparable, while prices are dynamically rescaled to reflect increasing returns to scale. Our approach allows us to model many scenarios of technology substitution and provides a method for generalizing market forces. With this model, we begin to forecast irreversible trends associated with consumer dynamics as well as policies that could be made to influence transition