We built a model of knowledges diffusion in networks. The particularity is that knowledges to be passed on are cumulative : rely on previous acquisition of specific knowledges of a lower level to be passed from an agent to another. We test for different types of networks, different selection rules for the knowledge to be passed and the possibility to introduce a turnover among agents.
We concentrate on the learning speed and the convergence level of the learning process.

The model studies the dynamics of risk-sharing cooperatives among heterogeneous farmers. Based on their knowledge on their risk exposure and the performance of the cooperative farmers choose whether or not to remain in the risk-sharing agreement.

We propose an ABM replicating the evolution of action oriented groups (like NPO) due to disagreement among members on the practices to implement. Looking at the stability and representativeness (ability of groups to federate) we introduce vertical communication: the possibility for group to communicate around their practices to their members. We test for three levels (to whom it is addressed) and four types (how it influences agents) of communication.