Nestedness

Nestedness is a common pattern in bipartite (mutualistic) networks, where a connection of a node tends to be a subset of interactions that higher-degree nodes possess. In the case of a country-exported product network, the strongly nested structure can be interpreted as: “the countries that export few products only make those that can be produced by others; the countries that export many products can make those that cannot be produced by many others.” In other words, it can suggest strong inequality and capability gaps.

Measuring Nestedness: A comparative study of the performance of different metrics may be a nice and recent review of nestedness.

According to the paper “Breaking the Spell of Nestedness: The Entropic Origin of Nestedness in Mutualistic Systems”, nestedness may be simply an entropic consequence of the degree sequence.

Isocline of perfect nestedness (IPN): the curve of a perfectly sorted matrix where both rows and columns are sorted to satisfy the definition of perfect nestedness.

Measures

• Atmar and Patterson temperature
• NODF

Tools

• https://github.com/cclaualc/nullnest: a package for constructing null models for nestedness computation.

References

• The Dynamics of Nestedness Predicts the Evolution of Industrial Ecosystems
• Factors Determining Nestedness in Complex Networks

Core periphery structure

• Network nestedness as generalized core-periphery structures