The Effects of Political Advertising on Facebook and Instagram before the 2020 US Election

This paper was conducted as part of the U.S. 2020 Facebook and Instagram Election Study, a collaboration between a team of researchers at Meta and an independent set of external academic researchers. The team designed the project together (with lead academic authors having final say on the pre-registered analysis plan). Data collection was carried out by Meta and NORC. The pipeline code used to pre-process raw platform data was conducted by Meta and reviewed and approved by the external researchers; both the Meta team and external researchers analyzed the data. The paper was written by the external researchers with feedback from the Meta team, but the lead academic authors had final control rights over text and publication. More details on the collaboration appear in the Competing Interests Section and in Supplementary Note 9. The Facebook Open Research and Transparency (FORT) team provided substantial support in executing the overall project. We are grateful for support on various aspects of project management from C. Nayak, S. Zahedi, I. Rosenn, L. Ahmad, A. Bhalla, C. Chan, A. Gruen, B. Hillenbrand, D. Li, P. McLeod, and D. Rice; engineering from Y. Chen, S. Chen, T. Lohman, R. Pyke, and Y.Wan; data engineering from S. Chintha, J. Cronin, D. Desai, Y. Kiraly, T. Li, X. Liu, S. Pellakuru, C. Xie, and B. Xiong; data science and research from H. Connolly-Sporing; academic partnerships from R. Mersey, M. Zoorob, L. Harrison, S. Aisiks, Y. Rubinstein and C. Qiao; privacy and legal assessment from K. Benzina, F. Fatigato, J. Hassett, S. Iyengar, P. Mohassel, A. Muzaffar, A. Raghunathan and A. Sun; and content design from C. Bernard, J. Breneman, D. Leto and S. Raj. NORC at the University of Chicago partnered with Meta on this project to conduct the fieldwork with the survey participants and pair the survey data with web tracking data for consented participants in predetermined aggregated forms. We are particularly grateful for the partnership of NORC principal investigator J. M. Dennis and NORC project director M. Montgomery. The costs associated with the research (such as participant fees, recruitment, and data collection) were paid by Meta, who collaborated with academics in this project as part of the U.S. 2020 Facebook and Instagram Election Study (for more details see Supplementary Note 9). Ancillary support (for example, research assistants and course buyouts), as applicable, was sourced by academics from (authors’ initials in parenthesis): the Democracy Fund (NJS), the European Research Council Starting Grant (EXPO- 756301) (MW), the Guggenheim Foundation (BN), the Hewlett Foundation (NJS, JT), the Hopewell Fund (JT), the John S. and James L. Knight Foundation (DF, DL, NJS, JT, RT), the Charles Koch Foundation (JT), New York University (JT), the Alfred P. Sloan Foundation (MG), Stanford University (HA, MG, NM, JP), the Stanford Institute for Economic Policy Research (MG), the University of Texas at Austin (NJS), and the University of Wisconsin–Madison (YMK). These funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.