6 results on '"Chessa, Alessandro"'
Search Results
2. The Accounting Network: How Financial Institutions React to Systemic Crisis.
- Author
-
Puliga, Michelangelo, Flori, Andrea, Pappalardo, Giuseppe, Chessa, Alessandro, and Pammolli, Fabio
- Subjects
FINANCIAL institutions ,FINANCIAL crises ,FINANCIAL statements ,BANKING industry ,BUSINESS enterprises ,SYSTEM analysis - Abstract
The role of Network Theory in the study of the financial crisis has been widely spotted in the latest years. It has been shown how the network topology and the dynamics running on top of it can trigger the outbreak of large systemic crisis. Following this methodological perspective we introduce here the Accounting Network, i.e. the network we can extract through vector similarities techniques from companies’ financial statements. We build the Accounting Network on a large database of worldwide banks in the period 2001–2013, covering the onset of the global financial crisis of mid-2007. After a careful data cleaning, we apply a quality check in the construction of the network, introducing a parameter (the Quality Ratio) capable of trading off the size of the sample (coverage) and the representativeness of the financial statements (accuracy). We compute several basic network statistics and check, with the Louvain community detection algorithm, for emerging communities of banks. Remarkably enough sensible regional aggregations show up with the Japanese and the US clusters dominating the community structure, although the presence of a geographically mixed community points to a gradual convergence of banks into similar supranational practices. Finally, a Principal Component Analysis procedure reveals the main economic components that influence communities’ heterogeneity. Even using the most basic vector similarity hypotheses on the composition of the financial statements, the signature of the financial crisis clearly arises across the years around 2008. We finally discuss how the Accounting Networks can be improved to reflect the best practices in the financial statement analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
3. Voting Behavior, Coalitions and Government Strength through a Complex Network Analysis.
- Author
-
Dal Maso, Carlo, Pompa, Gabriele, Puliga, Michelangelo, Riotta, Gianni, and Chessa, Alessandro
- Subjects
VOTING research ,SOCIAL network analysis ,POLITICAL science ,COALITIONS ,ITALIAN politics & government - Abstract
We analyze the network of relations between parliament members according to their voting behavior. In particular, we examine the emergent community structure with respect to political coalitions and government alliances. We rely on tools developed in the Complex Network literature to explore the core of these communities and use their topological features to develop new metrics for party polarization, internal coalition cohesiveness and government strength. As a case study, we focus on the Chamber of Deputies of the Italian Parliament, for which we are able to characterize the heterogeneity of the ruling coalition as well as parties specific contributions to the stability of the government over time. We find sharp contrast in the political debate which surprisingly does not imply a relevant structure based on established parties. We take a closer look to changes in the community structure after parties split up and their effect on the position of single deputies within communities. Finally, we introduce a way to track the stability of the government coalition over time that is able to discern the contribution of each member along with the impact of its possible defection. While our case study relies on the Italian parliament, whose relevance has come into the international spotlight in the present economic downturn, the methods developed here are entirely general and can therefore be applied to a multitude of other scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
4. Cluster Analysis of Weighted Bipartite Networks: A New Copula-Based Approach.
- Author
-
Chessa, Alessandro, Crimaldi, Irene, Riccaboni, Massimo, and Trapin, Luca
- Subjects
- *
BIPARTITE graphs , *COPULA functions , *MULTIVARIATE analysis , *METHODOLOGY , *STOCHASTIC analysis - Abstract
In this work we are interested in identifying clusters of “positional equivalent” actors, i.e. actors who play a similar role in a system. In particular, we analyze weighted bipartite networks that describes the relationships between actors on one side and features or traits on the other, together with the intensity level to which actors show their features. We develop a methodological approach that takes into account the underlying multivariate dependence among groups of actors. The idea is that positions in a network could be defined on the basis of the similar intensity levels that the actors exhibit in expressing some features, instead of just considering relationships that actors hold with each others. Moreover, we propose a new clustering procedure that exploits the potentiality of copula functions, a mathematical instrument for the modelization of the stochastic dependence structure. Our clustering algorithm can be applied both to binary and real-valued matrices. We validate it with simulations and applications to real-world data. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
5. The Rise of China in the International Trade Network: A Community Core Detection Approach.
- Author
-
Zhu, Zhen, Cerina, Federica, Chessa, Alessandro, Caldarelli, Guido, and Riccaboni, Massimo
- Subjects
INTERNATIONAL trade ,BUSINESS networks ,COMPUTER science ,GLOBALIZATION ,LEADERSHIP - Abstract
Theory of complex networks proved successful in the description of a variety of complex systems ranging from biology to computer science and to economics and finance. Here we use network models to describe the evolution of a particular economic system, namely the International Trade Network (ITN). Previous studies often assume that globalization and regionalization in international trade are contradictory to each other. We re-examine the relationship between globalization and regionalization by viewing the international trade system as an interdependent complex network. We use the modularity optimization method to detect communities and community cores in the ITN during the years 1995–2011. We find rich dynamics over time both inter- and intra-communities. In particular, the Asia-Oceania community disappeared and reemerged over time along with a switch in leadership from Japan to China. We provide a multilevel description of the evolution of the network where the global dynamics (i.e., communities disappear or reemerge) and the regional dynamics (i.e., community core changes between community members) are related. Moreover, simulation results show that the global dynamics can be generated by a simple dynamic-edge-weight mechanism. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
6. Cluster analysis of weighted bipartite networks: A new copula-based approach
- Author
-
Massimo Riccaboni, Irene Crimaldi, Alessandro Chessa, Luca Trapin, Alessandro, Chessa, Irene, Crimaldi, Massimo, Riccaboni, Trapin, Luca, Chessa, Alessandro, Crimaldi, Irene, and Riccaboni, Massimo
- Subjects
FOS: Computer and information sciences ,Genetics and Molecular Biology (all) ,Theoretical computer science ,Clustering, complex network, copula function, positional analysis, weighted bipartite network ,Economics ,Binary number ,Social Sciences ,lcsh:Medicine ,Bioinformatics ,Biochemistry ,Copula (probability theory) ,Mathematical and Statistical Techniques ,Sociology ,Theoretical ,Models ,Algorithms ,Humans ,Cluster Analysis ,Computer Simulation ,Models, Theoretical ,Medicine (all) ,Biochemistry, Genetics and Molecular Biology (all) ,Agricultural and Biological Sciences (all) ,lcsh:Science ,Physics ,Multidisciplinary ,Commerce ,Computer Science - Social and Information Networks ,Clustering, Copula, Bipartite Networks ,Mathematical instrument ,Social Networks ,Physical Sciences ,Bipartite graph ,Network Analysis ,Statistics (Mathematics) ,Network analysis ,Research Article ,Physics - Physics and Society ,Computer and Information Sciences ,Econophysics ,FOS: Physical sciences ,Physics and Society (physics.soc-ph) ,Research and Analysis Methods ,Statistical Methods ,Cluster analysis ,jel:C6 ,Social and Information Networks (cs.SI) ,lcsh:R ,Statistical model ,Probability and statistics ,International Trade ,Physics - Data Analysis, Statistics and Probability ,jel:F1 ,Settore SECS-P/05 - ECONOMETRIA ,lcsh:Q ,Data Analysis, Statistics and Probability (physics.data-an) ,Mathematics - Abstract
In this work we are interested in identifying clusters of "positional equivalent" actors, i.e. actors who play a similar role in a system. In particular, we analyze weighted bipartite networks that describes the relationships between actors on one side and features or traits on the other, together with the intensity level to which actors show their features. The main contribution of our work is twofold. First, we develop a methodological approach that takes into account the underlying multivariate dependence among groups of actors. The idea is that positions in a network could be defined on the basis of the similar intensity levels that the actors exhibit in expressing some features, instead of just considering relationships that actors hold with each others. Second, we propose a new clustering procedure that exploits the potentiality of copula functions, a mathematical instrument for the modelization of the stochastic dependence structure. Our clustering algorithm can be applied both to binary and real-valued matrices. We validate it with simulations and applications to real-world data.
- Published
- 2014
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.