Exploring ideological signals from cosponsorship

ABSTRACT While cosponsorship is a useful tool for cosponsors, what is its impact on the bill? Adapting the mathematical concept of directed transportation networks for the American Congressional context, we suggest cosponsorship’s impact on a bill comes in the form of an ideological signal. We offer a model of policymaking where ideological “weight” is added to bills each time legislators sign on as cosponsors. In addition to policy substance, the bill’s final position in ideological space may also be considered as a function of all collaborators (i.e., initial sponsor and cosponsors). We conclude by extending and applying our model to two bills from the 115th U.S. House. Results comport with our model’s expectations, suggesting we are capturing ideological signals from cosponsorship.