DyXi

Dynamiques Citadines Collectives : Hétérogénéités Spatiales et Individuelles

Urban Collective Dynamics: Individual and Spatial Heterogeneities

Projet bénéficiant d'une aide de l'ANR (Agence Nationale de la Recherche) dans le cadre du programme "Systèmes complexes et modélisation mathématique" (SYSCOMM), contrat ANR-08-SYSC-008

Project supported by the Program SYSCOMM of the French National Research Agency, the ANR.


DyXi news and events

Events organized by DyXi

Publications

Papers in peer-reviewed journals

  • M Barthélémy, J-P Nadal & H. Berestycki, "Disentangling collective trends from local dynamics", Proceedings  of the National Academy of Sciences (PNAS) [online April 12, 2010].

  • H. Berestycki and J-P Nadal, "Self-organised critical hot spots of criminal activity", European Journal of Applied Mathematics (EJAM), 2010 [sous presse].

  • François J.C., "La ségrégation sociale dans l'espace scolaire francilien au lendemain de l'« abandon » du principe de sectorisation", in: Données Urbaines n°6, Pumain D. & Mattei M.F. Coord., Economica, coll. Villes, 2010 [à paraître].

  • M.B. Gordon. "A random walk in the literature on criminality: a partial and critical view on some statistical analysis and modeling approaches", European Journal of Applied Mathematics (EJAM), 2010 [sous presse].

  • L. Gauvin, J-P Nadal & J. Vannimenus, "Schelling segregation in an open city: a kinetically constrained Blume-Emery-Griffiths spin-1 system", Phys. Rev. E 81, 066120,2010.

  • M. B. Gordon, J. R. Iglesias, V. Semeshenko & J.-P. Nadal, "Crime and punishment: the economic burden of impunity", European Physical Journal B, Volume 68, number 1, 2009,  pp.133-144.

  • J.-P. Nadal, M.B. Gordon, J. R. Iglesias et V. Semeshenko. "Modelling the individual and collective dynamics of the propensity to offend", European Journal of Applied Mathematics (EJAM), 2010 [sous presse].

  • L. Gauvin, J. Vannimenus & J-P Nadal, “Phase diagram of a Schelling segregation model”, European Physical Journal B, Volume 70:2, 2009, pp. 293-304 (DOI: 10.1140/epjb/e2009-00234-0)

  • Gordon, M. B., Iglesias, J. R., Semeshenko, V. & Nadal, J. P., “Crime and punishment: the economic burden of impunity”, European Physical Journal B, Volume 68, number 1, 2009,  pp.133-144

Book chapters

  • Banos A., Phan D., Sanders L., 2010, "Des contextes dans les modèles spatiaux à la modélisation des contextes spatiaux", Actes des XVIIèmes Rencontres de Rochebrune, janvier 2010 [forthcoming].

  • D. Phan, “Other dependent preferences and moral sentiments in cognitive economics models: first steps towards a more “generalized” rational choice model”,  in Raymond Boudon: A Life in Sociology, Edited by M. Cherkaoui and P. Hamilton, The Bardwell Press, forthcoming.

Conferences, workshops

  • L. Gauvin, oral communication at The 2009 European Conference on Complex Systems, Warwick, 21-25 Sept. 2009.

  • D. Phan & R. Waldeck, "Social norms, emotions and cooperation in groups". The 2009 European Conference on Complex Systems, Warwick, 21-25 Sept. 2009.

  • L. Gauvin, Poster, Congrès de la Société Française de Physique, 6-10 juillet 09, Palaiseau.

  • J-C. François et L. Sanders, "Pratiques de scolarisation et différenciation sociale de l’espace scolaire : 4 modèles pour un seul homme", communication au séminaire de Géographie-cités, Marly-le-Roi, 18-19 mai 2009

  • M. B. Gordon and J.-P. Nadal, Invited talks at the Workshop ANR-NSF on Dynamics in the Human Sciences: Cognitive, Behavioral, & Social Complexity, 27 et 28 avril 2009 Reims.

DyXi partners

  • CNRS CAMS (Centre d'Analyse et Mathématique Sociales, UMR 8557 CNRS & EHESS)
    École des Hautes Etudes en Sciences Sociales, Paris
    Contact : Jean-Pierre Nadal (DyXi Coordinator)

  • CNRS LPS (Laboratoire de Physique Statistique, UMR 8550 CNRS ENS Paris 6 & Paris 7)
    École Normale Supérieure, Paris
    Contact : Jean Vannimenus

  • CNRS GEMAS (Groupe d'Étude des Méthodes de l'Analyse Sociologique, UMR 8598 CNRS & Université Paris IV Sorbonne)
    Maison des Sciences de l'Homme, Paris
    Contact : Denis Phan

  • TELECOM Bretagne, LUSSI (Département Logique des Usages, Sciences Sociales et de l'Information, TELECOM Bretagne)
    TELECOM Bretagne, Brest
    Contact : Roger Waldeck

DyXi people

 (non-comprehensive list, alphabetical order; in [ ], corresponding DyXi Partner):

Image1Le projet DyXi

Dans ce projet de recherche fondamentale, nous nous proposons d’utiliser des techniques de modélisation de systèmes complexes dans l’étude des interactions sociales et spatiales en contexte urbain : il s’agit de repérer, expliquer, anticiper des patterns (statiques ou dynamiques) macroscopiques qui émergent lorsque le comportement de chaque individu est non seulement dépendant de facteurs idosyncratiques, mais est aussi influencé par le comportement des autres, ou par les croyances de l’individu [sur le comportement ou sur les croyances des autres, ou sur le pattern macroscopique lui-même (sur le comportement collectif)]. Dans ce cadre général, nous nous focaliserons plus particulièrement sur trois aspects :

(1) incivilités et criminalité ; (2) ségrégation urbaine ; (3) ségrégation scolaire.

Les modèles seront construits à partir de l’analyse de données empiriques (concernant principalement Paris, mais aussi les banlieues parisiennes et Lyon), et feront appel à des techniques de la physique statistique des systèmes désordonnés, à de la dynamique des populations, et à l’approche multi-agents. L’analyse statistique permettra d’extraire des faits stylisés et les variables pertinentes. La modélisation aura pour but d’une part de dégager les mécanismes responsables de ces faits stylisés, et d’identifier les propriétés génériques ou au contraire spécifiques, et d’autre part, à chaque fois que cela sera possible, de rendre compte quantitativement des faits observés. La modélisation – et en particulier la simulation - permettra aussi de tester l’effet de différentes politiques. Enfin les interactions entre les travaux sur les trois domaines choisis serviront de base à une réflexion générale sur la constitution de « normes » sociales en contexte urbain - l’adoption de règles implicites communes, de comportements collectifs (méta)stables au sein de la population. Au-delà de la seule comparaison avec les données, la validation et la critique des modèles ferra largement appel à l’expertise des chercheurs en SHS impliqués dans le projet.

Image2The DyXi Project

This basic research project, conducted by an interdisciplinary team, uses techniques of complex system modelling in the study of social and spatial interactions in an urban setting. The aim is to identify, explain and anticipate the (static or dynamic) macroscopic patterns that emerge when the behaviour of each individual is not only dependent on idiosyncratic factors, but also influenced by “the others”. The main objective of this work is to explain the social phenomena that shape the dynamics of urban segregation. Three major objects are studied:

(1) antisocial behaviour and criminality, (2) urban segregation and housing, (3) school segregation,

all three taken as measurements of social and spatial inequality.The models will be constructed on the basis of the analysis of empirical data, exploiting techniques drawn from the statistical physics of disordered systems, population dynamics and the multi-agent approach.

For the theme “urban segregation and housing”, the aim is to explain the influence of social segregation on the price formation of urban housing, taking into account the heterogeneity of individuals and the dynamics of their interactions. We incorporate into models inspired by statistical physics not only the income gaps in populations but also the dynamics of housing prices. We hypothesise that the price of housing is linked not only to its intrinsic characteristics, but also to what could be called its neighbourhood characteristics, which can evolve. By explicitly taking these effects into account, we shall explain the mechanisms at work in the evolution of a district, bringing to light the conditions under which mixed equilibriums will emerge (social mix), or separating equilibria (distinct sites of “gentrification” and pauperisation).

As regards the theme of “school segregation”, the originality of our proposition lies in the way we take into account the context of the pupils and the establishment, on several levels. Here, our aim is to account for the effects of feedback between pupil behaviour and the dynamic of the setting in which they go to school. The aim is to modelise the choice of school made by families, with the help of a multi-agent system, drawing on the data and expertise of sociologists and geographers. By means of simulations, the model will enable us to test the effects of the abolition of pre-defined catchment areas on social and school heterogeneity. The main objectives are to better understand the rationales at work in the choice of school, by taking into account the different heterogeneities, evaluating the social and spatial inequalities in access to education and their dynamics, and then to forecast the main trends in the social division of schooling in the Ile de France region.

As far as the “antisocial behaviour and criminality” theme is concerned, we shall be seeking to modelise in a domain where little such work has been carried out. One of our first steps will be to draw up an original database. We shall then modelise crime in economic terms with direct application to the criminality of young people in an urban setting. Lastly, we shall consider the theoretical aspects of criminality, like the possibility of an epidemiological approach with analysis of the dynamics and characterisation of fluctuations in crime rates.

Contact:

Jean-Pierre Nadal

CAMS, EHESS

54, bd Raspail - 75270 Paris cedex 06

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