From the paper: The conventional understanding of how elected officials affect the policy agenda is based in arguments that they use symbols... Show moreFrom the paper: The conventional understanding of how elected officials affect the policy agenda is based in arguments that they use symbols and rhetoric to propagate the problem, and that this happens primarily through the traditional media. The arguments presented in this article are largely consistent with this but account for the function of social media. More specifically, and framed by indexing theory, we argue that social media enhances opportunities for policy agenda builders in the U.S. Congress to share information with journalists. Across the key policy issues of 2013, tests for congruence between politicians’ Twitter posts and New York Times articles confirm a connection, particularly for the policy issue areas of the economy, immigration, health care, and marginalized groups. Simultaneous discussion and debate between Democrats and Republicans about a particular policy issue area, however, negatively impacts how the New York Times indexes a particular issue. Here we provide single Excel file of all the hashtags posted by members of Congress to Twitter during 2013. The file contains three columns: datetime, hashtag, and twitter_username. The datetime indicates when a tweet was posted. The hashtag indicates what hashtag a user posted at that time (tweets may contain multiple tags). Twitter_username is the Twitter handle of the account that posted a tweet with that hashtag at that time. We created a list of member of Congress Twitter accounts by looking up each member and checking with Govtrack.us and congress.gov information. Please cite our paper: Shapiro, M. A. and Hemphill, L. (in press) Agenda Building & Indexing: Does the U.S. Congress Direct New York Times Content through Twitter? Policy & Internet. Show less