Calendrier du 01 février 2017
Economic History Seminar
Du 01/02/2017 de 12:30 à 14:00
Salle 8, RDC Bâtiment G, Campus Jourdan, 48 boulevard Jourdan, 75014 Paris
CASARI Marco (University of Bologna)
Group size and collective action: learning from six centuries of management of the commons in the Italian Alps
écrit avec Marco Casari and Claudio Tagliapietra
Cooperation is challenging in large groups. Here we study what is the group size that characterizes well-functioning social-ecological systems. We consider systems where groups harvest a common resource and govern it through collective deliberations. Through an in depth study of hundreds of communities over six centuries, we report a remarkable long term stability in group size at around 150. This figure is determined by social rather than ecological factors. To maintain a constant size in the presence of population growth, groups engaged in fissions. Moreover, social heterogeneity shaped both group size and institutional complexity. What limits group size seems to be a "Double Bound:" individual cognition constraints in keeping track of resource users as well as the need to reach coherent collective decisions.