structural:reformatting, stylistic:style_transfer
Strategies

Traditional ground campaigning and voter contacts remain the most effective strategies. Some research suggests that knocking on doors can increase turnout by as much as 10% and phone calls by as much as 4%. One study suggests that lawn signs increase vote share by 1.7 percentage points. A review of more than 200 get-out-the-vote experiments finds that the most effective tactics are personal: Door-to-door canvassing increases turnout by an average of about 2.5 percentage points; volunteer phone calls raise it by about 1.9 points, compared to 1.0 points for calls from commercial phone banks; automated phone messages are ineffective. Using out-of-state volunteers for canvassing is less effective in increasing turnout than using local and trained volunteers.

According to political scientists Donald Green and Alan Gerber, it costs $31 to produce a vote going door to door, $91-$137 to produce a vote by sending out direct mailers, $47 per vote from leafletting, $58-$125 per vote from commercial phone banking, and $20-$35 per vote from voluntary phone banking. A 2018 study in the American Economic Review found that door-to-door canvassing on behalf of the Francois Hollande campaign in the 2012 French presidential election "did not affect turnout, but increased Hollande's vote share in the first round and accounted for one fourth of his victory margin in the second. Visits' impact persisted in later elections, suggesting a lasting persuasion effect." According to a 2018 study, repeated get-out-the-vote phone calls had diminishing effects but each additional phone call increased the probability to vote by 0.6-1.0 percentage points. Another 2018 study found that "party leaflets boost turnout by 4.3 percentage points while canvassing has a small additional effect (0.6 percentage points)" in a United Kingdom election.

A 2016 study found that visits by a candidate to states have modest effects: "visits are most effective in influencing press coverage at the national level and within battleground states. Visits' effects on voters themselves, however, are much more modest than consultants often claim, and visits appear to have no effects outside the market that hosts a visit." The authors of the study argue that it would be more effective for campaigns to go to the pockets of the country where wealthy donors are (for fundraising) and hold rallies in the populous states both to attract national press and raise funds. A 2005 study found that campaign visits had no statistically significant effect, after controlling for other factors, on voter turnout in the 1992, 1996, and 2000 elections. On the other hand, a 2017 paper of the 1948 presidential election provides "strong evidence that candidate visits can influence electoral returns". Other research also provides evidence that campaign visits increase vote share.

Campaigns may also rely on strategically placed field offices to acquire votes. The Obama 2008 campaign's extensive use of field offices has been credited as crucial to winning in the states of Indiana and North Carolina. Each field office that the Obama campaign opened in 2012 gave him approximately a 0.3% greater vote share. According to one study, the cost per vote by having a field office is $49.40.

According to a 2020 study, campaign spending on messaging to voters affects voter support for candidates. Another 2020 study found that political advertising had small effects regardless of context, message, sender, and receiver. A 2022 study found that voters are persuadable to switch support for candidates when they are exposed to new information.

Political science research generally finds negative advertisement (which has increased over time) to be ineffective both at reducing the support and turnout for the opponent. A 2021 study in the American Political Science Review found that television campaign ads do affect election outcomes, in particular in down-ballot races. According to political scientists Stephen Ansolabehere and Shanto Iyengar, negative ads do succeed at driving down overall turnout though. A 2019 study of online political advertising conducted by a party in the 2016 Berlin state election campaign found that the online-ad campaign "increased the party's vote share by 0.7 percentage points" and that factual ads were more effective than emotional ads.