In International Economics, so-called gravity equation has been successful. In the present paper, we show that similar equation concerning transaction network holds well. The weight of transaction network among Japanese prefectures is explained by Sales-i*Sales-j/Distance-ij very well. The...

We study evolutionary learning processes through social networks. We show that network heterogeneity, in particular scale-freeness, enhances social learning by studying a model in which an agent set on a network imitates the strategy only from the neighborhood. Further, in order to determine...