Cosponsorship networks reveal which lawmakers’ support helps bills pass

Researchers have developed a network-based measure of influence among members of the United States House of Representatives that appears to help explain why some bills pass and others fail. The study, published in EPJ Data Science, builds its measure from the pattern of bill cosponsorship in the House, awarding influence between a pair of lawmakers when they cosponsor a bill that achieves some amount of legislative success.

Each year, the United States Congress considers thousands of legislative proposals to select bills to present to the US President to sign into law. The researchers, Sarah Sotoudeh, Mason A. Porter and Sanjukta Krishnagopal, examined how the decision processes of members of Congress are subject to peer influence, focusing specifically on whether a bill passes in the House.

To capture influence, the team analyzed the structure of a network constructed from cosponsorship dynamics. When two members of Congress cosponsor the same bill and that bill goes on to achieve legislative success, the pair is credited with influence. Aggregating these credits across many bills produces a measure of how much accrued influence surrounds a given bill through its cosponsors.

The study then explored how the influence of a bill’s cosponsors affects the bill’s outcome. According to the authors, properties of the bill cosponsorship network can be a useful signal to examine influence in Congress, and these properties help explain why some bills pass and others fail in the House.

A key part of the analysis was a comparison against conventional centrality measures, which are standard tools in network science for identifying important nodes in a network. The researchers concluded that their influence measure is more indicative of bill passage than these conventional centrality measures, suggesting that the specific way influence is accrued through successful cosponsorship carries information that standard centrality does not.

The work sits within a broader research tradition that treats legislatures as networks, with lawmakers as nodes and legislative interactions as ties. Earlier studies cited by the journal as related work have examined hidden coalitions in the House by partitioning signed networks, omnibus legislating in the US Congress, and polarization and influential nodes in spheres of legislation. The new study adds to this line of work by tying a concrete legislative outcome, House passage, to a measure of influence derived from cosponsorship behavior.

The measure is descriptive rather than a claim of causal manipulation. The authors define influence operationally, through cosponsorship of bills that achieve some amount of legislative success, and they report that the resulting network properties help explain bill outcomes. The abstract does not report effect sizes, predictive accuracy figures or a claim that influence causes passage, and the paper’s stated conclusion is that the influence measure is more indicative of bill passage than conventional centrality measures.

Because the analysis concerns the United States House of Representatives, its scope is that chamber and its cosponsorship dynamics. The abstract describes the construction of the network from cosponsorship dynamics and the comparison with centrality measures, without detailing the time period of the data, the number of bills analyzed or the specific statistical methods used to test the association between influence and passage.

The study is published as open access research in EPJ Data Science, with the article shared early to provide faster access to peer-reviewed, accepted research. The authors report that the decision processes of members of Congress are naturally subject to peer influence, and their findings indicate that the structure of the cosponsorship network, as summarized by their influence measure, can serve as a useful signal for examining influence in Congress and for understanding which bills are more likely to pass.

Subject of Research: A network-based measure of cosponsorship influence on bill passage in the United States House of Representatives

Article Title: A network-based measure of cosponsorship influence on bill passage in the United States House of Representatives

Article References: Sotoudeh, S., Porter, M. A., & Krishnagopal, S. (2026). A network-based measure of cosponsorship influence on bill passage in the United States House of Representatives. EPJ Data Science. https://doi.org/10.1140/epjds/s13688-026-00689-4

Image Credits: AI Generated

DOI: 10.1140/epjds/s13688-026-00689-4

Keywords: US House of Representatives, bill cosponsorship, network analysis, legislative influence, bill passage, centrality measures, Congress, EPJ Data Science, computational social science, peer influence, network-based, measure