Detecting coalitions by optimally partitioning signed networks of political collaboration
Samin Aref, Zachary Neal
备注:
21 pages, 10 figures, 4 tables (including supplementary information) Old title: Legislative effectiveness hangs in the balance: Studying balance and polarization through partitioning signed networks
发表信息:
AREF, S., and NEAL, Z. Detecting coalitions by optimally partitioning signed networks of political collaboration. Scientific Reports, (2020), www.doi.org/10.1038/s41598-020-58471-z
We propose new mathematical programming models for optimal partitioning of a signed graph into cohesive groups. To demonstrate the approach's utility, we apply it to identify coalitions in US Congress since 1979 and examine the impact of polarized coalitions on the effectiveness of passing bills. Our models produce a globally optimal solution to the NP-hard problem of minimizing the total number of intra-group negative and inter-group positive edges. We tackle the intensive computations of dense signed networks by providing upper and lower bounds, then solving an optimization model which closes the gap between the two bounds and returns the optimal partitioning of vertices. Our substantive findings suggest that the dominance of an ideologically homogeneous coalition (i.e. partisan polarization) can be a protective factor that enhances legislative effectiveness.
University of Sydney(悉尼大学);Goethe University Frankfurt(法兰克福歌德大学);IT:U Interdisciplinary Transformation University(IT:U跨学科转型大学);Central European University(中欧大学);Complexity Science Hub(复杂性科学中心)
Leveraging Content Producer Networks and User Perception to Detect Online Discursive Communities
National Research Council of Italy, Institute for Applied Mathematics(意大利国家研究委员会应用数学研究所);LUISS “Guido Carli” University(卢伊斯·圭多·卡尔利大学);National Research Council of Italy, Institute of Complex Systems(意大利国家研究委员会复杂系统研究所);Ca’ Foscari University of Venice(威尼斯卡福斯卡里大学);London Institute for Mathematical Sciences(伦敦数学科学研究所);“Enrico Fermi” Research Center(恩里科·费米研究中心);IMT School for Advanced Studies Lucca(卢卡高等研究学院)