[eng] While adopting an approach of innovation diffusion in terms of interacting agents, we emphasise the role of cumulated influence in the context of social networks. We first introduce a cumulative effect in the classical epidemic model which involves a slower starting phase followed by a...

[eng] The role of social networks in innovation diffusion remains a strategic question. In former works, we have introduced a relational learning, based on hebbian rule, that leads to a critical state, in which few agents reach structural positions of opinion leaders. In this paper, we show that...

[eng] A recent literature studies economic situations where agents have to form links with others for strategic goals. A major contribution in this field is the focus on dilemmas between stable networks - in the sense of strategie interests - and efficient networks - in the sense of maximization...

A set of agents is organized in a social network, which conveys synergies in two activities. Each agent has one unit of a resource to allocate between two activities. We show that individual choices are shaped by Bonacich centrality measures and an attractiveness multiplier. The latter, combined...

We consider a model of interdependent efforts, with linear and possibly asymmetric interaction. We examine how a variation of the intensity of interaction affects aggregate effort. We show that the relevant information is given by the transposed system.

This article explores individual incentives to produce information on communication networks. In our setting, efforts are strategic complements along communication paths with possible decay. We analyze Nash equilibria on the line network. We give conditions under which more central agents...

We present a model of communication network formation in which links'strengths are endogenously determined by individual incentives. Agents are endowed with a fixed amount of resource which they can distribute as they want in directed links. Individuals capture benefits from both direct and...

This article explores individual incentives to produce information on communication networks. In our setting, efforts are strategic complements along communication paths with convex decay. We analyze Nash equilibria on a set of networks which are unambiguous in terms of centrality. We first...

This paper describes inter-firm partnerships in three major high-tech industries over the 1985-2005 period. We found that the architecture of the respective networks had evolved toward a ‘small world' in the early 1990s. We also found that the number of alliances collapsed in the late 1990s....

We consider a Cournot oligopoly setting in which consumers have an intrinsic preference for variety, while unit production costs of firms increase with the number of goods they produce. This environment exhibits a general under-provision of variety with respect to social welfare.