1. Department of Economics, Stanford University, Stanford, CA 94305
2. Meta, Menlo Park, CA 94025
3. Data Science Lab, Hertie School, Berlin 10117, Germany
4. University of North Carolina Hussman School of Journalism and Media, University of North Carolina, Chapel Hill, NC 27514
5. Annenberg School for Communication, University of Pennsylvania, Philadelphia, PA 19104
6. Department of Politics and School of Public and International Affairs, Princeton University, Princeton, NJ 08540
7. School of Journalism and Mass Communication, University of Wisconsin-Madison, Madison, WI 53706
8. Northeastern University Lab of Texts, Maps, and Networks, Northeastern University, Boston, MA 02115
9. Graduate School of Business, Stanford University, Stanford, CA 94305
10. Department of Government, Dartmouth College, Hanover, NH 03755
11. Department of Communication, Stanford University, Stanford, CA 94305
12. Department of Government, William & Mary, Williamsburg, VA 23185
13. Department of Political Science, Syracuse University, Syracuse, NY 13244
14. School of Media and Public Affairs and Institute for Data, Democracy, and Politics, George Washington University, Washington, DC 20052
15. Department of Communication, University of California Davis, Davis, CA 95616
16. Amsterdam School of Communication Research, University of Amsterdam, Amsterdam 15791, Netherlands
17. Moody College of Communication, University of Texas at Austin, Austin, TX 78712
18. Wilf Family Department of Politics and Center for Social Media and Politics, New York University, New York, NY 10012