The Role of Social Network in Migration and Economic Aggregation Through a Brownian Agent Model

Abstract

This chapter extends an established model of Brownian agent to investigate the role of social networks in migration and economic aggregation under a multiregion system. The regional conditions are represented by three variables: wage level, tax rate, and welfare. In the model, Brownian agents make their movements by exploiting their social networks to find regional locations with better incomes. We examined the model under four types of network structures: (1) complete network, (2) random network, (3) regular network, and (4) scale-free network. Via computer simulations, the results prove that social networks affect agent migration and economic aggregation and reduce the stability of the whole system. Some findings are summarized as follows: 1. Regardless of the network structure, agents always move to locations with a high welfare service. 2. Agents move frequently when the network has highly connected links (complete and random network) and no obvious economic center appears and remains, whereas in the case of a loosely connected network (regular and scale-free network), agents mainly migrate to regions with a high tax rate for better welfare; the multiregion system finally evolves toward a stable state.