In many social networks, there is a high correlation between the similarity of actors and the existence of relationships between them. This paper introduces a model of network evolution where actors are assumed to have a small aversion from being connected to others who are dissimilar to themselves, and yet no actor strictly prefers a segregated network. This model is motivated by Schelling's [...

I use a simple model of social dilemmas arising from environmental problems to study the effects of certain stylized solution strategies. It is often a central characteristic of these environmental dilemmas that action effects are spatially concentrated, i.e. the strength of side effects of individual actions declines with the distance to the source of pollution. I use computer simulations base...

This research questions how social media use affords new forms of organizing and collective engagement. The concept of connective action has been introduced to characterize such new forms of collective engagement in which actors coproduce and circulate content based upon an issue of mutual interest. Yet, how the use of social media actually affords connective action still needed to be investiga...

In multi-actor systems, coordinated action is achieved by processes of mutual adjustment that can take the form of organizing, planning, and improvisation. A plan can be seen as a social construct, a relatively persistent socially shared unit of knowledge, reinforced in its existence by its daily use. In order to be able to understand multi-actor planning this chapter investigates the questions...

Recently, there has been an increasing interest in how strategic action influences network structure. Motivated by the widespread belief that ‘networks matter’ in the process of reaching personal objectives, it is a natural assumption that rational actors will try to strategically arrange their ties in order to optimize their expected utility. Starting from the notion that there exist rival the...

Emotions play an essential role in the behaviour of human beings, either at their sudden occurrence or by the continuous care to prevent the occurrence of unpleasant ones and to search for the occurrence of pleasant ones. Notably, in any system of collective action, they influence the behaviours of the actors with respect to each others. SocLab is a framework devoted to the study of the functio...

This article complements the substantial body of literature produced over the last three decades on the export of hazards from developed countries to developing countries. After reviewing the central arguments proposed by this literature, the authors add to the debate by focusing on the role of national actors in the importation of these hazards, based on the experience of late 1970s' developme...

Individual and organizational actors enter into a large number of relationships that include benefiting others without ensuring the equality of reciprocal benefits. We suggest that actors have evolved mechanisms that guide them in the choice of exchange partners, even without conscious calculation or bookkeeping of gain and loss. One such mechanism directs actors to membership in clusters, whic...

In recent years there has been a growing interest in inferring social relations amongst actors in a video using audiovisual features, co-appearance features or both. The discovered relations between actors have been used for identifying leading roles, detecting rival communities in a movie plot etc. In this paper we propose an unsupervised method which uses the video’s transcript and closed cap...

Participatory GIS projects are increasingly popular in urban governance. This paper explores the complexities of a community involved pilot project that was implemented in the town of Verona, Wisconsin and critically examines their GIS (Geographic Information Systems) practices and the support structures that played an important role in facilitating GIS use. The paper first traces the evolution...