10,097 research outputs found
Community Structure in the United States House of Representatives
We investigate the networks of committee and subcommittee assignments in the
United States House of Representatives from the 101st--108th Congresses, with
the committees connected by ``interlocks'' or common membership. We examine the
community structure in these networks using several methods, revealing strong
links between certain committees as well as an intrinsic hierarchical structure
in the House as a whole. We identify structural changes, including additional
hierarchical levels and higher modularity, resulting from the 1994 election, in
which the Republican party earned majority status in the House for the first
time in more than forty years. We also combine our network approach with
analysis of roll call votes using singular value decomposition to uncover
correlations between the political and organizational structure of House
committees.Comment: 44 pages, 13 figures (some with multiple parts and most in color), 9
tables, to appear in Physica A; new figures and revised discussion (including
extra introductory material) for this versio
Quantifying discrepancies in opinion spectra from online and offline networks
Online social media such as Twitter are widely used for mining public
opinions and sentiments on various issues and topics. The sheer volume of the
data generated and the eager adoption by the online-savvy public are helping to
raise the profile of online media as a convenient source of news and public
opinions on social and political issues as well. Due to the uncontrollable
biases in the population who heavily use the media, however, it is often
difficult to measure how accurately the online sphere reflects the offline
world at large, undermining the usefulness of online media. One way of
identifying and overcoming the online-offline discrepancies is to apply a
common analytical and modeling framework to comparable data sets from online
and offline sources and cross-analyzing the patterns found therein. In this
paper we study the political spectra constructed from Twitter and from
legislators' voting records as an example to demonstrate the potential limits
of online media as the source for accurate public opinion mining.Comment: 10 pages, 4 figure
Community Structure in Congressional Cosponsorship Networks
We study the United States Congress by constructing networks between Members
of Congress based on the legislation that they cosponsor. Using the concept of
modularity, we identify the community structure of Congressmen, as connected
via sponsorship/cosponsorship of the same legislation, to investigate the
collaborative communities of legislators in both chambers of Congress. This
analysis yields an explicit and conceptually clear measure of political
polarization, demonstrating a sharp increase in partisan polarization which
preceded and then culminated in the 104th Congress (1995-1996), when
Republicans took control of both chambers. Although polarization has since
waned in the U.S. Senate, it remains at historically high levels in the House
of Representatives.Comment: 8 pages, 4 figures (some with multiple parts), to appear in Physica
A; additional background info and explanations added from last versio
Mining and Analyzing the Italian Parliament: Party Structure and Evolution
The roll calls of the Italian Parliament in the XVI legislature are studied
by employing multidimensional scaling, hierarchical clustering, and network
analysis. In order to detect changes in voting behavior, the roll calls have
been divided in seven periods of six months each. All the methods employed
pointed out an increasing fragmentation of the political parties endorsing the
previous government that culminated in its downfall. By using the concept of
modularity at different resolution levels, we identify the community structure
of Parliament and its evolution in each of the considered time periods. The
analysis performed revealed as a valuable tool in detecting trends and drifts
of Parliamentarians. It showed its effectiveness at identifying political
parties and at providing insights on the temporal evolution of groups and their
cohesiveness, without having at disposal any knowledge about political
membership of Representatives.Comment: 27 pages, 14 figure
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Friends in High Places
We demonstrate that personal connections amongst U.S. politicians have a significant impact on Senate voting behavior. Networks based on alumni connections between politicians are consistent predictors of voting behavior. We estimate sharp measures that control for common characteristics of the network, as well as heterogeneous impacts of a common network characteristic across votes. We find that the effect of alumni networks is close to 60% as large as the effect of state-level considerations. The network effects we identify are stronger for more tightly linked networks, and at times when votes are most valuable. We show that politicians use school ties as a mechanism to engage in vote trading ("logrolling"), and that alumni networks help facilitate the procurement of discretionary earmarks
SOCIAL CAPITAL AT THE CAPITOL: A SOCIAL NETWORK ANALYSIS OF INTEREST GROUP INFLUENCE IN THE 111th CONGRESS
This dissertation builds on existing scholarship in political science and political sociology to explore the influence of interest groups in legislative action networks. The primary theoretical insight is that as the number of interest group affiliations between two members of Congress increases, so does the frequency with which they forge other sorts of social ties necessary to advance the interests of their interest group constituencies. In particular, the analysis looks at interest group donation strategies, legislative co-sponsorships, and roll-call votes during the 111th Congress (2009-2010). The analysis uses social network analysis methods to create network models of 19 different policy domains, as well as an aggregate model, for both the House and Senate. Legislator ideology, state, committee assignments, and experience have a generally significant impact on the number of interest group affiliations shared by each pair of legislators, whereas gender, race/ethnicity, office location and occupational history do not. The results show that interest groups do have consistent impact over co-sponsorships in the House, but somewhat more mixed influence in the Senate. In some instances, groups in the policy domain encourage policy change, and in other instances, status quo protection. The theory did not anticipate the latter effect, though it does make sense in context of other research findings. For roll-call votes, interest groups have a significant influence over some House policy domains but not many Senate policy domains. The increased polarization of the Senate, necessity of minority party discipline to maximize their leverage through use of the filibuster, and staggered nature of Senate elections makes interest group influence tougher to muster in the upper chamber of Congress
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