From Ecology to Finance (and Back?): Recent Advancements in the Analysis of Bipartite Networks

TL;DR

This paper reviews recent interdisciplinary advancements in bipartite network analysis, emphasizing entropy-based null models that are versatile, analytically tractable, and applicable across ecological and economic systems.

Contribution

It introduces and discusses entropy-based bipartite null models, highlighting their analytical, versatile, and interdisciplinary applications in analyzing complex bipartite networks.

Findings

Entropy-based models provide effective benchmarks for null hypothesis testing.

These models successfully reconstruct network configurations from partial data.

They are applicable to ecological and economic bipartite systems.

Abstract

Bipartite networks provide an insightful representation of many systems, ranging from mutualistic networks of species interactions to investment networks in finance. The analysis of their topological structures has revealed the ubiquitous presence of properties which seem to characterize many - apparently different - systems. Nestedness, for example, has been observed in plants-pollinator as well as in country-product trade networks. This has raised questions about the significance of these patterns, which are often believed to constitute a genuine signature of self-organization. Here, we review several methods that have been developed for the analysis of such evidence. Due to the interdisciplinary character of complex networks, tools developed in one field, for example ecology, can greatly enrich other areas of research, such as economy and finance, and vice versa. With this in mind, we briefly review several entropy-based bipartite null models that have been recently proposed and discuss their application to several real-world systems. The focus on these models is motivated by the fact that they show three very desirable features: analytical character, general applicability and versatility. In this respect, entropy-based methods have been proven to perform satisfactorily both in providing benchmarks for testing evidence-based null hypotheses and in reconstructing unknown network configurations from partial information. On top of that, entropy-based models have been successfully employed to analyze ecological as well as economic systems, thus representing an ideal, interdisciplinary tool to approach the study of bipartite complex systems. [...]