Node-weighted interacting network measures improve the representation of real-world complex systems

TL;DR

This paper introduces a new set of statistical measures for analyzing networks of interacting systems with heterogeneous node weights, improving the understanding of complex real-world systems like trade networks.

Contribution

The paper develops and validates a novel class of node-weighted interacting network measures that better capture the structure of complex, interdependent systems.

Findings

Node-weighted measures outperform unweighted ones in representing system properties.

Application to EU trade networks reveals insights into trade balance and economic robustness.

Method enhances analysis of systems with varying node importance.

Abstract

Network theory provides a rich toolbox consisting of methods, measures, and models for studying the structure and dynamics of complex systems found in nature, society, or technology. Recently, it has been pointed out that many real-world complex systems are more adequately mapped by networks of interacting or interdependent networks, e.g., a power grid showing interdependency with a communication network. Additionally, in many real-world situations it is reasonable to include node weights into complex network statistics to reflect the varying size or importance of subsystems that are represented by nodes in the network of interest. E.g., nodes can represent vastly different surface area in climate networks, volume in brain networks or economic capacity in trade networks. In this letter, combining both ideas, we derive a novel class of statistical measures for analysing the structure of networks of interacting networks with heterogeneous node weights. Using a prototypical spatial network model, we show that the newly introduced node-weighted interacting network measures indeed provide an improved representation of the underlying system's properties as compared to their unweighted analogues. We apply our method to study the complex network structure of cross-boundary trade between European Union (EU) and non-EU countries finding that it provides important information on trade balance and economic robustness.