ONLINE APPENDIX:
Leaders or Followers? Measuring Political Responsiveness in the U.S. Congress Using Social Media Data.
Pablo Barberá, Richard Bonneau, Patrick Egan, John Jost, Jonathan Nagler, and Joshua Tucker

Economic Issues

Topic 13: Small Business
Topic 17: 2013 Government Shutdown (Republicans)
Topic 26: 2013 Government Shutdown (Democrats)
Topic 35: 2013 Budget Sequestration (Republicans)
Topic 37: Social Security
Topic 38: Budget Discussion (early 2014)
Topic 39: Keystone XL Pipeline
Topic 42: 2013 Budget Sequestration (Democrats)
Topic 46: Unemployment Numbers Reports
Topic 47: Paul Ryan's Budget Proposal
Topic 49: 2013 Budget Agreement
Topic 53: Minimum Wage
Topic 59: Budget Discussion (mid-2014)
Topic 64: FAA Furloughs Cause Flight Delays
Topic 70: #MiddleClassFirst campaign
Topic 83: 21st Century Cures Initiative
Topic 93: Jobs Bills Omnibus

Foreign Policy

Topic 7: 100 Days of #BringBackOurGirls campaign
Topic 23: #BringBackOurGirls campaign
Topic 32: Islamic State
Topic 33: Use of Military Force in Syria
Topic 36: Ebola
Topic 66: Malaysian Airlines Crash in Ukraine
Topic 69: Sargent Tahmooressi Release
Topic 97: Protests in Ukraine and Venezuela
Topic 99: CIA Detentions and Interrogations Report

Social Issues

Topic 9: Gender Wage Gap
Topic 11: Hobby Lobby Supreme Court Decision (Democrats)
Topic 14: Marriage Equality
Topic 15: Gun Violence
Topic 16: Abortion (Pro-Life)
Topic 27: Student Debt (2014)
Topic 28: Employment Non-Discrimination Act
Topic 41: Immigration (Border Security)
Topic 43: Executive Action on Immigration
Topic 50: Climate Change
Topic 56: Student Debt (2013)
Topic 58: Affordable Care Act
Topic 62: Border Crisis in Texas
Topic 63: Obamacare (Employer Mandate)
Topic 67: Comprehensive Immigration Reform
Topic 74: Hobby Lobby Supreme Court Decision (Republicans)
Topic 75: Military Justice Improvement Act
Topic 81: Poverty (SNAP program)
Topic 85: Unemployment Insurance
Topic 89: Obamacare (Website and Implementation)
Topic 96: Violence Against Women Act
Topic 100: #ObamacareInThreeWords Campaign

Political Scandals

Topic 3: Investigation of Attack on American Embassy in Benghazi
Topic 18: Veteran Affairs Delays Scandal
Topic 20: NSA Surveillance Scandal
Topic 88: IRS Scandal

Anniversaries and Celebrations

Topic 1: Anniversary of the Civil Rights Act
Topic 5: Memorial Day
Topic 10: Thanksgiving
Topic 24: Deaths of Mandela, Thatcher, Lautenberg
Topic 30: Valentine's Day
Topic 48: Black History Month
Topic 60: Family Holidays
Topic 61: Appreciation Days (Mother, Teacher...)
Topic 68: Martin Luther King
Topic 72: Christmas Holidays
Topic 73: Birthday Celebrations
Topic 77: Flag Day
Topic 78: Constitution Day
Topic 79: Earth Day
Topic 82: Labor Day
Topic 87: Entrepeneurs Day and World Aids Day
Topic 91: Father's Day and St. Patrick's Day
Topic 94: Boston Marathon Attack and Tax Day
Topic 98: Veterans Day

Legislative Activity

Topic 12: Republican Issues, Spring 2013
Topic 25: Gold Medal Awards
Topic 34: Weekly GOP Address
Topic 40: Congressional Arts Competition
Topic 51: Lame Duck Congress
Topic 54: Republican Issues, 2014
Topic 65: Constituency Visits
Topic 84: Media Appearances by House Republicans
Topic 86: Legislative Activity by House Democrats
Topic 90: State of the Union Address
Topic 92: Democratic Issues, Early 2013
Topic 95: 113th Congress Inauguration

General Vocabulary

Topic 4: Public Communication by House Republicans
Topic 8: Public Communication by Senate Republicans
Topic 19: General Vocabulary (All)
Topic 21: General Vocabulary (Senate)
Topic 29: General Vocabulary (House)
Topic 31: Public Communication by House Democrats
Topic 44: Public Communication by Senate Democrats

Other

Topic 2: Severe Weather in Oklahoma
Topic 6: Prayers & Thoughts After Disasters
Topic 22: Follow Friday Tweets (#FF)
Topic 45: Photos Posted on Facebook
Topic 52: Winter Weather
Topic 55: Soccer World Cup
Topic 57: Election Day 2014
Topic 71: 2014 Winter Olympics
Topic 76: Cory Booker
Topic 80: Fort Hood Shooting