During this week, we will discuss how to use difference-in-differences and event study approaches to estimate the causal effect of a given event or policy on social media behavior.

Presentations

Karin, Emma, and Signe are presenting:
Exposure to opposing views on social media can increase political polarization
Christopher Bail, Lisa Argyle, Taylor Brown, John Bumpus, Haohan Chen, M. B. Fallin Hunzaker, Jaemin Lee, Marcus Mann, Friedolin Merhout, and Alexander Volfovsky (2018)

Frederik is presenting:
Political Advertising Online and Offline
Erika Franklin Fowler, Michael M. Franz, Gregory J. Martin, Zachary Peskowitz, and Travis N. Ridout (2018)

Readings

The first reading concerns a well-known and extensively used research design for causal inference called a difference-in-differences design. If you already know this design, please read only the subsection regarding event studies here. If you’ve never heard of difference-in-differences, please read the entire chapter. If you already know differences-in-differences and event study models, then just read the 2 applied readings.

The two applied readings this week (readings 2 and 3) are each relatively short. The first of these is the one that we will work through in the lab. I have also included an optional but longer applied reading (further below) because it is very well known, and was highly covered by the media when it came out. It concerns the effects of Mohammad Salah joining Liverpool FC on racist sentiment.

  1. Causal Inference: The Mixtape (Ch. 9 only)
    Yale University Press, 2021
    Scott Cunningham

  2. Do Violent Protests Affect Expressions of Party Identity? Evidence from the Capitol Insurrection
    American Political Science Review, 2023
    Gregory Eady, Frederik Hjorth, and Peter Thisted Dinesen

  3. Collaborative Adding Context to Social Media Posts Reduces the Sharing of False News
    Working paper, 2024
    Thomas Renault, David Restrepo-Amariles, and Aurore Troussel-Clément

  4. The Pandemic and Gender Inequality in Academia
    PS: Political Science & Politics, 2022
    Eunji Kim and Shawn Patterson, Jr.

Optional

  1. Can Exposure to Celebrities Reduce Prejudice? The Effect of Mohamed Salah on Islamophobic Behaviors and Attitudes
    American Political Science Review, 2022
    Ala’ Alrababa’h, William Marble, Salma Mousa, and Alexandra Siegel
    - Coverage of the article in The Economist here

Lecture

For reference, these are the two classic articles on difference-in-differences:

  1. The Impact of the Mariel Boatlift on the Miami Labor Market
    Industrial and Labor Relations Review, 1990, 43 (2): 245-257.
    David Card

  2. Minimum Wages and Employment: A Case Study of the Fast-Food Industry in New Jersey and Pennsylvania
    Industrial and Labor Relations Review, 1994, 84 (4): 772-793.
    David Card and Alan B. Krueger

Lab

Reference code from the video tutorial: Event_Study_Lab.R
Twitter profile data (anonymized): IdPol_Anonymized.csv.bz2