In an effort to conceptually replicate prior work on persuasion and campaign effects, we conducted three randomized survey experiments to evaluate the persuasive effects of political advertisements during the 2025 Canadian federal election. We tested a total of 15 campaign advertisements on 3,346 respondents. Our results are consistent with what seems to be three robust findings about the effects of campaign advertising: (1) they can change candidate evaluations and vote intentions, but (2) the effects are very small, and most importantly, (3) persuasive treatment effects seem to be mostly homogeneous. We offer new empirical evidence that strengthens previous findings on the homogeneity of persuasive treatment effects of political advertising in Canada that challenges the extent to which microtargeting improves candidates and advocacy groups’ ability to sway public opinion.

Do retrospective and prospective messages about judicial candidates influence participation in individual state high court races? To answer this question, I examine the effect of television ads for judicial candidates on ballot rolloff in state high court elections from 2000 to 2018. I find that increased exposure to ads with higher proportion of retrospective messages has diminishing returns, as more exposure to these ads increases the average rolloff per judicial election and per judicial race. Despite concerns about candidates announcing what they will do once they are elected, I find no relationship between prospective messages and voter participation given increased exposure to ads containing such messages. These results suggest that exposure to a candidate’s record may both mobilize and fatigue voters, and that concerns about prospective rhetoric may be exaggerated.

As digital platforms become a key channel for political advertising, there are continued calls for expanding regulation of digital political ads as a distinct content category. However, designing policies to meet these demands requires us first to decipher what the public perceives a “political” ad to be. In this article, we report two preregistered experiments to understand factors that drive public perceptions of what makes an ad political. We find that both advertiser-level cues and content-level cues play an independent role in shaping perceptions. To a lesser extent, participants also attribute political meaning to ads that clash with their own preferences. These patterns were replicated in a conjoint study using artificial ads and in an experiment using real-world ads drawn from the Facebook Ad Library. Our findings serve as an important benchmark for evaluating proposed definitions of political ads from policymakers and platforms.

Presidential primary elections arguably represent the most dynamic campaigns in American politics. Television advertising is a key aspect of strategy that candidates can marshal throughout the campaign. We develop a methodology for measuring the impact of advertising in primary elections that accounts for endogeneity and apply it to the 2000 through 2016 elections. We find that advertisements—both positive and negative—improve the favorability and the vote share of the candidate running the ads. We find that negative advertising is more effective than positive advertising, but that only high polling candidates lose support when attacked.

This paper is concerned with the legal and regulatory control of electoral campaigning online, in particular ‘microtargeting’. There has been a longstanding consensus in the UK on how to control political advertising, yet the shift of expenditure to the online environment, together with innovations in digital campaigning tools, are exposing tensions and gaps in the current regime. One central harm associated with microtargeting is its potential to undermine meaningful democratic deliberation. The paper interrogates the issues through the lens of electoral law and regulation, and questions the extent to which a recalibration is necessary to deal with the challenges of digital campaigning.

This study evaluates the turnout effects of direct mail sent in advance of the 2014 New Hampshire Senate election. Registered Republican women were sent up to 10 mailings from a conservative advocacy group that encouraged participation in the upcoming election. We find that mail raises turnout, but no gains are achieved beyond five mailers. This finding is shown to be consistent with other experiments that have sent large quantities of mail. We interpret these results in light of marketing research on repetitive messaging.

I argue that candidates shape their issue agendas—the sets of related issues on which they focus—in part in response to the issue agendas of their opponents and that competitive campaigns stimulate candidates to respond to one another at higher rates. I test my theory of candidate interaction using weekly advertising data at the media market level from 146 statewide elections—54 gubernatorial and 92 U.S. Senate contests—from six election years and across all 50 states. I find that candidates systematically respond to one another's issue agendas and do so to a greater extent in competitive elections than in noncompetitive elections.