Party Comrades and Constituency Buddies: Determinants of Private Initiative Cosponsor Networks in a Parliamentary Multiparty System

TL;DR

This paper analyzes the determinants of private initiative cosponsor networks among Members of Parliament in a European multiparty system, revealing party and constituency influences on legislative and budget motion networks.

Contribution

It introduces network detection algorithms to identify core communities in MP cosponsorship patterns and compares determinants across different network types.

Findings

Legislative networks are mainly characterized by party affiliations.

Budget motion networks are primarily influenced by MPs' constituencies.

Committee assignments and gender are not significant factors.

Abstract

We study Members of Parliament (MP) private initiative (bill) cosponsor patterns from a European parliamentary multiparty perspective. By applying network detection algorithms, we set out to find the determinants of the cosponsorship patterns. The algorithms detect the initiative networks core communities, after which the variables characterizing the core communities can be analyzed. We found legislative network communities being best characterized by the MPs' party affiliations. The budget motion networks, which constitute roughly half of the data, were found mostly characterized by the MPs' home constituencies and only to a limited extent by the MPs' party affiliations. In comparison to previous findings regarding certain presidential systems, MPs committee assignments or gender were found irrelevant.