Vital Statistics on Congress
Data on the US Congress – A Joint Effort from Brookings, the American Enterprise Institute, and the Campaign Finance Institute

US Capitol Hill dome detail at night by

For more than three decades, "Vital Statistics on Congress," a joint effort undertaken by Norman Ornstein of the American Enterprise Institute and Thomas Mann of the Brookings Institution, in collaboration with Michael Malbin of the Campaign Finance Institute, has been a go-to reference guide for congressional watchers for impartial data on Congress and its members. 

Note: Video and statistical graphics produced by The Brookings Institution. 

Vital Stats full data set PDF

Download PDF
The purpose of "Vital Statistics" has always been to collect useful data on our first branch of government — on the election and composition of its membership as well as its formal procedure, such as the use of the filibuster, informal norms, party structure, and staff. This data set also documents the increasing polarization of Congress and the demographics of those who serve in the US Senate and US House of Representatives.

Over the years, we’ve received innumerable requests for updated versions of the chapters in between printings of the published book. We heard you and have now changed the way we present the "Vital Statistics" data: we’ve put the book online, making each chapter available online as a collection of spreadsheets for download at no cost. This new interactive format allows us to update and correct the data more frequently and make it accessible to anyone interested in learning about Congress. We’ve formatted the tables so that each is both printer-friendly and read-writable.

We encourage you to share your feedback and how you’ve used this data set, and we plan on posting your most interesting findings. Find out how you can submit your own "Vital Stats" analyses through the Brookings Institution

Chapter 1: Demographics of Members of Congress

Who are our members of Congress, what are their backgrounds, and from which part of the country do they come? This chapter provides data on apportionment, partisan makeup, and regional party representation of each Congress, as well as demographic information on members, such as geographic origins, seniority status, prior occupations, religious affiliation, and ethnicity. 

Read the full Chapter 1 summary on
Download the Chapter 1 data as a PDF.
Download the Chapter 1 data in Excel.

Chapter 2: Congressional Elections

Chapter 2 offers information on the results of US congressional elections, including reelection rates, seats that changed parties, elections won with significant majorities, and those that were close. Data also compare the district-level vote for president and for the district’s representative, and conditions of election for the 112th and 113th Congresses.

Read the full Chapter 2 summary on
Download the Chapter 2 data as a PDF.
Download the Chapter 2 data in Excel.

Chapter 3: Campaign Finance in Congressional Elections

How much money do successful congressional candidates spend to win a seat in the Senate or the House? Chapter 3 details campaign finance expenditures by members of Congress, as well as the spending habits of political action committees. Data include the cost of winning an election by year, how much incumbents spent on their reelection campaigns, and total funds national party committees raise. The data was compiled by the experts at the Campaign Finance Institute. 

Read the full Chapter 3 summary on
Download the full Chapter 3 data as a PDF.
Download the Chapter 3 data in Excel.

Chapter 4: Congressional Committee Data

Chapter 4 explores the size and quantity of congressional committees in the House and the Senate. Data include the type of committees active in each Congress, how many committees members of Congress have been assigned, and the majority chairmanships of congressional committees.

Read the full Chapter 4 summary on
Download the full Chapter 4 data as a PDF.
Download the full Chapter 4 data in Excel.

Chapter 5: Congressional Staff and Operating Expenses

Chapter 5 enumerates the size of congressional staff — for individual members as well as for committees — and the appropriations for member offices.

Read the full Chapter summary on
Download the full Chapter 5 data as a PDF.
Download the full Chapter 5 data in Excel.

Chapter 6: Legislative Productivity in Congress and Workload

How much has each Congress accomplished over the years, and how does the most recent Congress’ productivity compare to those of legislative bodies past? Chapter 6 reviews legislative productivity in the House and Senate over time, providing detailed data on number and length of bills passed, recorded votes in both chambers, and the use of cloture motions in the Senate, among other data points.

Read the full Chapter 6 summary on
Download the full Chapter 6 data as a PDF.
Download the full Chapter 6 data in Excel.

Chapter 7: Congressional Action on the Federal Budget

Chapter 7’s tables provide insight into Congress’ work on the federal budget, including votes in both chambers on adopting budget resolutions and other budget-related measures, spending and appropriations, and the use of continuing resolutions to keep the government funded.

Read the full Chapter 7 summary on
Download the full Chapter 7 data as a PDF.
Download the full Chapter 7 data in Excel.

Chapter 8: Political Polarization in Congress and Changing Voting Alignments

Chapter 8 documents the rise in political polarization in Congress and trends in voting alignment. The data include ideological scores for House and Senate party coalitions and committees, party unity votes and scores, and roll call votes on bills on which the president has taken an official stance.

Read the full Chapter 8 summary on
Download the full Chapter 8 data as a PDF.
Download the full Chapter 8 data in Excel.


Summary text was written by The Brookings Institution. Chapter 3 data compiled by the Campaign Finance Institute. 


Michael J. Malbin, cofounder and the executive director of the Campaign Finance Institute (CFI), is also a professor of political science at the University at Albany, State University of New York (SUNY). One of the country’s leading scholars in this field, he has been writing extensively about money and politics for more than three decades. Before SUNY, he had been a reporter for National Journal and a resident fellow at the American Enterprise Institute and held positions in the House of Representatives and Defense Department.



Thomas E. Mann is the W. Averell Harriman Chair and senior fellow in Governance Studies at The Brookings Institution. Between 1987 and 1999, he was director of governmental studies at Brookings. Before that, Mann was executive director of the American Political Science Association. Mann is a fellow of the American Academy of Arts and Sciences and a member of the Council on Foreign Relations. He is a recipient of the American Political Science Association’s Frank J. Goodnow and Charles E. Merriam Awards.


Norman Ornstein is a longtime observer of Congress and politics. He is a contributing editor and columnist for National Journal and The Atlantic and is an election eve analyst for BBC News. He served as codirector of the AEI-Brookings Election Reform Project and participates in AEI's Election Watch series. Ornstein led a group of scholars and practitioners that helped shape the law, known as McCain-Feingold, that reformed the campaign financing system. He was elected as a fellow of the American Academy of Arts and Sciences.



Andrew Rugg is a Research Assistant at the American Enterprise Institute where he focuses on public opinion polling and Congress. He is co-host of AEI’s Banter podcast.






The following individuals made recent contributions to "Vital Statistics on Congress":

  • Jonathan Achard, AEI intern
  • Clement Bilhorn, AEI intern
  • Avram Billig, Brookings intern
  • Nick Davis, AEI intern
  • Elana Firsht, Brookings intern
  • Wylie Galvin, AEI intern
  • Robyn Giannini, AEI intern
  • Brendan Glavin, Campaign Finance Institute
  • Daniel Guenther, Brookings intern
  • Lauren Hitt, AEI intern
  • Kenneth Meyer, Brookings intern
  • Jane Makin, AEI intern
  • Jennifer Marsico, AEI
  • Jordan Miller, AEI intern
  • Michael Parrot, Campaign Finance Institute
  • Cameron Petty, AEI intern
  • James Pickens, AEI intern
  • Molly Reynolds, Brookings
  • Timothy Ryan, AEI
  • Brent Scher, AEI intern
  • William Schultz, AEI intern
  • Henrik Temp, AEI
  • Raffaela Wakeman, Brookings
  • Matt Weil, AEI
  • Tom Weingartner, AEI intern
  • Min Yoo, AEI intern
Also Visit
AEIdeas Blog The American Magazine
About the Author


Norman J.



What's new on AEI

AEI Election Watch 2014: What will happen and why it matters
image A nation divided by marriage
image Teaching reform
image Socialist party pushing $20 minimum wage defends $13-an-hour job listing
AEI on Facebook
Events Calendar
  • 27
  • 28
  • 29
  • 30
  • 31
Monday, October 27, 2014 | 10:00 a.m. – 11:30 a.m.
State income taxes and the Supreme Court: Maryland Comptroller v. Wynne

Please join AEI for a panel discussion exploring these and other questions about this crucial case.

Tuesday, October 28, 2014 | 9:30 a.m. – 12:15 p.m.
For richer, for poorer: How family structures economic success in America

Join Lerman, Wilcox, and a group of distinguished scholars and commentators for the release of Lerman and Wilcox’s report, which examines the relationships among and policy implications of marriage, family structure, and economic success in America.

Tuesday, October 28, 2014 | 5:30 p.m. – 7:00 p.m.
The 7 deadly virtues: 18 conservative writers on why the virtuous life is funny as hell

Please join AEI for a book forum moderated by Last and featuring five of these leading conservative voices. By the time the forum is over, attendees may be on their way to discovering an entirely different — and better — moral universe.

Thursday, October 30, 2014 | 2:00 p.m. – 3:00 p.m.
A nuclear deal with Iran? Weighing the possibilities

Join us, as experts discuss their predictions for whether the United States will strike a nuclear deal with Iran ahead of the November 24 deadline, and the repercussions of the possible outcomes.

Thursday, October 30, 2014 | 5:00 p.m. – 6:15 p.m.
The forgotten depression — 1921: The crash that cured itself

Please join Author James Grant and AEI senior economists for a discussion about Grant's book, "The Forgotten Depression: 1921: The Crash That Cured Itself" (Simon & Schuster, 2014).

No events scheduled this day.
No events scheduled this day.
No events scheduled this day.
No events scheduled today.
No events scheduled this day.