The emergence of online political advertising has come with little regulation . As a result, social media platforms provide venues for political advertising with little accountabilityattached. Where accountability for political speech is lacking, we may expect the speech to be more divisive. This is particularly true for outside groups like Super PACs and dark money groups, most of whom disappear after elections. In this work, we analyze how campaign finance disclosure and microtargeting relate to the sentiment of political ads on Facebook. We obtained 790,303 ads from Facebook's political ad library that ran between August-November 2018. We compare ads run by candidates, parties, and two types of outside groups: those that disclose their donors and those that are funded by dark money . Dark money outside groups ran ads with the most negative sentiment on average, whereas candidates ran ads with the most positive sentiment . Outside groups ran 62\% of Facebook ads, with dark money ads outnumbering ads with more transparent campaign financing (3:2). A majority of ads (63\%) were microtargeted to less than 1000 Facebook users. Outside groups used microtargeting to run ads that have more negative sentiment, and candidates and parties used it to run ads with more positive sentiment . These results suggest that accountability for speech matters. Microtargeting of online political advertisements facilitates more extreme tonedifferences between outside groups and candidates, and advertising by more transparent URLanizations has more positive sentiment than advertising from less URLanizations .
The emergence of online political advertising has come with little regulation , allowing political advertisers on social media to avoid accountability. We analyze how transparency deficits caused by dark money and group impermanence relate to the sentiment of political ads on Facebook. We obtained 525,796 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 (i) their donor transparency (dark money or disclosed) and (ii) the group's permanence (disappearing after 2018 or re-registering). Ads run by dark money and disappearing outside groups were more negative than transparent and re-registering groups, respectively . Outside groups as a whole also ran more negative ads than candidates and parties . These results suggest that transparency for political speech is associated with advertising tone: the most negative advertising comes URLanizations with less donor disclosure and permanence .
R
. As a result, social media platforms provide venues for political advertising with little accountabilityattached. Where accountability for political speech is lacking, we may expect the speech to be more divisive. This is particularly true for outside groups like Super PACs and dark money groups, most of whom disappear after elections. In this work, we analyze how campaign finance disclosure and microtargeting
, allowing political advertisers on social media to avoid accountability. We analyze how transparency deficits caused by dark money and group impermanence
R
790,303 ads
525,796 ads with FEC-registered advertisers
D
political
R
two types of outside groups: those that disclose their donors and those that are funded
outside groups, which we classify by (i) their donor transparency (dark money or disclosed) and (ii) the group's permanence (disappearing after 2018 or re-registering). Ads run
R
. Dark money outside groups ran ads with the most negative sentiment on average, whereas candidates ran ads with the most positive sentiment
and disappearing outside groups were more negative than transparent and re-registering groups, respectively
R
ran 62\% of Facebook ads, with dark money ads outnumbering ads with more transparent campaign financing (3:2). A majority of ads (63\%) were microtargeted to less than 1000 Facebook users. Outside groups used microtargeting to run ads that have more negative sentiment, and
as a whole also ran more negative ads than
D
used it to run ads with more positive sentiment
R
accountability for speech matters. Microtargeting of online political advertisements facilitates more extreme tonedifferences between outside groups and candidates, and advertising by more transparent URLanizations has more positive sentiment than advertising from less URLanizations
transparency for political speech is associated with advertising tone: the most negative advertising comes URLanizations with less donor disclosure and permanence