Abstract
We propose a new approach based on bootstrapping to compare complex networks. This is an important task when we wish to compare the effect of a (policy) shock on the structure of a network. The bootstrap test compares two values of the Gini index, and the test is performed on the difference between them. The application is based on the interlocking directorship network. At the director level, Italian corporate governance is characterized by the widespread occurrence of interlocking directorates. Article 36 of Law 214/2011 prohibited interlocking directorates in the financial sector. We compare the interlocking directorship networks in 2009 (before the reform) with 2012 (after the reform) and find evidence of an asymmetric effect of the reform on the network centrality of the different companies but no significant effects on Gini indices.
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Notes
- 1.
In the simulations we have considered very general networks in which there are no effects caused by preferential attachment, triadic closure, clustering tendencies, constraints on the degree distribution due to transaction costs, which may characterize economic networks. The different additions/destructions of the links occur randomly. In the future, we will consider more complex cases that consider these features. These more complex structures may lead to complex reactions to the addition/destruction of the different nodes. In particular, the process of addition/destruction may be quicker or slower with the implication that the test may be more or less likely to reject the null hypothesis.
- 2.
Working with the projected two-mode would make it possible to analyze the inequality in degree both on the company and the director side.
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Acknowledgments
We would like to thank Paolo Santella and Antonio Balzanella for useful discussions and two anonymous reviewers for constructive comments. Any remaining errors are ours alone. A previous version of the paper was presented at the SIS 2015 Conference.
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Drago, C., Ricciuti, R. (2020). Bootstrapping the Gini Index of the Network Degree: An Application for Italian Corporate Governance. In: Ragozini, G., Vitale, M. (eds) Challenges in Social Network Research. Lecture Notes in Social Networks. Springer, Cham. https://doi.org/10.1007/978-3-030-31463-7_4
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