That's totally fair. I was being a bit flippant in my original comment. I was reacting to the idea that, a candidate spreading their message will impact what d

That's totally fair. I was being a bit flippant in my original comment. I was reacting to the idea that, a candidate spreading their message will impact what decision people make at the voting booth, and that in and of itself is obvious. If candidates said nothing, no one would vote for them, because no one would know anything about them. Surely that much is obvious. Yes, it's probably very difficult to prove the cost-benefit analysis of ads. At best, people hope that attack ads will reveal some information to people that will sway their decision (I perused through the papers you linked, but didn't see much about scandals). I also imagine ads are meant to generate buzz in the media, which can push a message to would-be voters, who can then keep spreading the message. The effect is likely over time, and extremely difficult to predict & prove due to many different ways people can interact with each other. Although that paper you linked on gullibility was..... odd. I don't know why the distinction of "content-based" gullibility vs. "source-based" gullibility is important or interesting. The authors are saying that.... fake news works? That also implies that advertising can work if it's delivered in a medium appearing as an authority, i.e. a media organization or research group. In other words, bad advertising doesn't work, but good advertising will. Surprise?