We analyze fundamental characteristics of the inter-firm transaction network through the data of 800,000 Japanese firms. We find that there exists a hierarchical structure and a negative degree correlation in this transaction network. We also find that this undirected network is a scale-free...

We found hierarchical structure and negative degree correlation in firms' transaction network. The network consists of 800,000 Japanese firms. We also summarize other features of the network and discuss why studying network structure is important. We also found scale free distribution in...

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...

We investigate a two-strategy logit choice coordination game on heterogeneous networks. We show that the heterogeneity of a network affects the outcome in that it determines the number of stable steady states and the properties of the states. The network heterogeneity also determines which of...

We study a coordination game in a network that indicates who plays with whom. A player chooses a strategy by logit choice. We show that in typical scale-free networks, one strategy always prevails by the neighborhood effect regardless of the values of parameters, while in regular networks, it...

We study a condition of favoring cooperation in a Prisoner's Dilemma game on complex networks. There are two kinds of players: cooperators and defectors. Cooperators pay a benefit b to their neighbors at a cost c, whereas defectors only receive a benefit. The game is a death-birth process with...

In this paper, we study imperfect competition on a scale-free network. A scale-free network is not exceptional but rather ubiquitous in reality. For this purpose, we construct a class of utility functions, from which relationships between firms in the form of networks are derived. A regional...