Facebook Political Ads And Accountability: Outside Groups Are Most Negative, Especially When Hiding Donors

TL;DR

The paper addresses how deficits in accountability—specifically dark money and disappearing outside groups—shape the sentiment of Facebook political ads. Using 430,044 ads from Aug–Nov 2018 and classifying advertisers by donor transparency and persistence, the authors apply VADER sentiment analysis and validate with RoBERTa-based models and LDA topic analysis. They find that dark money ads are significantly more negative, with the strongest negativity when the advertiser both lacks disclosure and disappears after an election (e.g., a drop of $-0.29$ with $p=0.002$). Donor transparency emerges as the primary driver of sentiment differences, implying that stronger disclosure requirements could reduce negativity in online political advertising and curb affective polarization on social media.$

Abstract

The emergence of online political advertising has come with little regulation, allowing political advertisers on social media to avoid accountability. We analyze how transparency and accountability deficits caused by dark money and disappearing groups relate to the sentiment of political ads on Facebook. We obtained 430,044 ads with FEC-registered advertisers from Facebook's ad library that ran between August-November 2018. We compare ads run by candidates, parties, and outside groups, which we classify by (1) their donor transparency (dark money or disclosed) and (2) the group's permanence (only FEC-registered in 2018 or persistent across cycles). The most negative advertising came from dark money and disappearing outside groups, which were mostly corporations or 501(c) organizations. However, only dark money was associated with a significant decrease in ad sentiment. These results suggest that accountability for political speech matters for advertising tone, especially in the context of affective polarization on social media.

Figures (2)

• Figure 1: Average Sentiment and Interquartile Range by Advertiser Type. The distribution of VADER sentiment scores is more negative for advertiser types with less accountability (by donor disclosure, group persistence, and categories of outside groups). The red center lines denote means, the box extends from the first quartile to the third quartile (IQR), and the whiskers extend from the box to 1.5x the IQR. The number of advertisements ($n$) is reported in blue on top of each category's left whisker.
• Figure 2: Estimated Sentiment (90% CI) by Accountability Based on Coefficients in Table 1 - Model (1)