Dynamic motifs in socio-economic networks

Socio-economic networks are of central importance in economic life.We develop a method of identifying and studying motifs in socio-economic networks by focusing on "dynamic motifs,"i.e., evolutionary connection patterns that, because of "node acquaintances "i n the net- work, occur much more frequently than random patterns. We examine two evolving bi-partite networks: i) the world-wide commercial ship chartering market and ii) the shipbuild-to-order market. We find similar dynamic motifs in both bipartite networks, eventhough they describe different economic activities. We also find that "influence" and "persistence" are strong factors in the interaction behavior of organizations. When two companies are doing business with the same customer, it is highly probable that another customer who currently only has business relationship with one of these two companies, will become customer of the second inthe future. This is the effect of influence. Persistence means that companies with close business ties to customers tend to maintain their relationships over a long period of time.