eprintid: 2249 rev_number: 25 eprint_status: archive userid: 6 dir: disk0/00/00/22/49 datestamp: 2014-07-07 10:24:01 lastmod: 2014-09-26 07:12:41 status_changed: 2014-09-25 09:24:53 type: monograph metadata_visibility: show creators_name: Dal Maso, Carlo creators_name: Pompa, Gabriele creators_name: Puliga, Michelangelo creators_name: Riotta, Gianni creators_name: Chessa, Alessandro creators_id: carlo.dalmaso@imtlucca.it creators_id: gabriele.pompa@imtlucca.it creators_id: michelangelo.puliga@imtlucca.it creators_id: creators_id: alessandro.chessa@imtlucca.it title: Voting behavior, coalitions and government strength through a complex network analysis ispublished: pub subjects: DG subjects: HB subjects: JC divisions: EIC full_text_status: public monograph_type: imt_eic_working_paper keywords: Parliamentary Network, Party Cohesion, Government Strength - JEL Code: D72 note: ArXiv version: http://arxiv.org/abs/1407.0913 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 establised 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. date: 2014-09-25 date_type: published number: 10 publisher: IMT Institute for Advanced Studies Lucca pages: 9 institution: IMT Institute for Advanced Studies Lucca issn: 2279-6894 citation: Dal Maso, Carlo and Pompa, Gabriele and Puliga, Michelangelo and Riotta, Gianni and Chessa, Alessandro Voting behavior, coalitions and government strength through a complex network analysis. EIC working paper series #10/2014 IMT Institute for Advanced Studies Lucca ISSN 2279-6894. document_url: http://eprints.imtlucca.it/2249/1/EIC_WP_10_2014.pdf