Three empirical studies on the aggregate dynamics of humanly driven complex systems

Complex systems are characterized by having emergent properties that cannot be explained from their large number of interacting and heterogeneous components. Different aspects of human society can be described as a complex system, as large numbers of people aggregate into a host of complex structures. Here we empirically study three different aspects of humanly driven complex systems. First, we study the dynamics of a mobile phone network reconstructed from millions of individual phone calls. By looking at time resolved data we show that the structure of the mobile phone network is coupled to the dynamics of mobile phone links. Second, we study the statistical properties of human mobility patterns and show that the characteristic distance travelled by individuals follows a heterogeneous distribution which explains the previously observed LÌÄå©vy-flight properties of human mobility. Third, we construct a network summarizing world trade to study the dynamics of countries productive structures and show that the structure of the product space conditions the industrial development of nations. These three studies illustrate how large data sets can be used to empirically study humanly driven complex systems. Individually, they present relevant information that can be used to benchmark future models for each one of these complex systems or can be used as empirical rules characterizing them.