Structure and evolution of a European Parliament via a network and correlation analysis

Abstract

We present a study of the network of relationships among elected members of the Finnish parliament, based on a quantitative analysis of initiative co-signatures, and its evolution over 16 years. To understand the structure of the parliament, we constructed a statistically validated network of members, based on the similarity between the patterns of initiatives they signed. We looked for communities within the network and characterized them in terms of members' attributes, such as electoral district and party. To gain insight on the nested structure of communities, we constructed a hierarchical tree of members from the correlation matrix. Afterwards, we studied parliament dynamics yearly, with a focus on correlations within and between parties, by also distinguishing between government and opposition. Finally, we investigated the role played by specific individuals, at a local level. In particular, whether they act as proponents who gather consensus, or as signers. Our results provide a quantitative background to current theories in political science. From a methodological point of view, our network approach has proven able to highlight both local and global features of a complex social system.

Covariance and correlation estimators in bipartite complex systems with a double heterogeneity

“…Concerning the Finnish parliament dataset (term 2011-2014), results reported in top-row panels of figure 6 show how the weighing destroys the cluster of party KESK, implying that this cluster is more due to the heterogeneity and consequent bias in the unweighted correlation estimator than to a real collaboration between MPs, while, at the same time, weighing preserves the cluster of party PS. This finding is in agreement with the general trend observed in [25], where the evolution of this network over four Finnish parliament terms is studied. In fact, during previous terms, MPs collaborated by district and by party both, with party being more characterizing in the opposition and district sub-clustering within the government.…”

“…Obviously, when going from Eq. (18) to Eq. (19), one needs first to remove all the values of w i q that are either 0, 1 or infinite.…”

“…The datasets taken into consideration are two, one pertains to the social sciences and the other one to the biological sciences. The social database [25] consists of 1808 private initiatives submitted between 2011 and 2014 by 201 members of the Finnish parliament (MPs), along with information on who signed each initiative. Data cover an entire parliament of the duration of four years.…”

Parliamentary roll-call voting as a complex dynamical system: The case of Chile

“…Some studies have explored the dynamics of legislative behavior using complex network and social network analysis [11][12][13][14]. Given that parliamentarians change in each legislative term, these analyses provide descriptions of local changes.…”