Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I even say who wrote them. If you have more recent summaries to add to this collection, send them my way I guess. Sorry for the ads; they cover the costs of keeping this online.
Clinton and Lapinski. 2004. "Targeted" advertising and voter turnout: An experimental study of the 2000 Presidential election. Journal of Politics 66.
There is a debate in the literature: Do negative advertisements increase ("stimulate") or decrease ("demobilize") turnout? The authors argue that neither is correct; instead, ads target specific issue publics and these issue publics respond to content regardless of tone ("differential effects").
The lit has been divided around two arguments. Since each is backed by evidence from different methods (lab experiments vs voter surveys), it's hard to compare the two.
Ansolabehere and Iyengar did all sorts of experimental studies that suggested that negative ads increase voter apathy and, therefore, decrease turnout. These effects are most pronounced on independents, since negative ads "Heighten the partisan flavor of political discourse."
Survey research (mainly ANES) suggests the opposite. Negative ads are at least as informative as positive ads; information increases interest; interest increases turnout; therefore, negative ads promote turnout (see Lau, for example).
Despite the lit's arguments, political consultants seem to think that "what matters most to voters in determining whether or not they vote are the issues and personalitities involved in the race" (p 72). They target their ads at various issue publics, which respond to the issue content of the ad regardless of tone. Since ads have different effects on different subgroups, this is the "differential effects" hypothesis.
An experimental panel survey. Some people are shown positive or negative ads during some of the surveys. Surveys are taken both before and after the 2000 election.
They used Knowledge Networks' panel. KN gives randomly selected volunteers the opportunity to have free internet and free WebTV if they agree to take a weekly survey.
Research on similar subjects