By ground or by air? Voter mobilization during the United States' 2008 presidential campaign

Aggregate studies find no effect of campaign advertising on voter turnout in the United States, thereby calling into question experimental and survey-based studies that produce strong turnout effects. In revisiting the debate over the impact of campaign ads, this paper examines the effects of both TV campaign advertising and campaign field offices on aggregate voter turnout during the 2008 US presidential election campaign. In contrast to previous studies, our analysis finds that both campaign field offices and campaign advertising help to stimulate turnout, although the effect of campaign field offices is more robust to alternative model specifications. We also find that only Obama's field offices had any discernible impact on aggregate voter turnout, thereby reinforcing the narrative that the Obama campaign had a superior ground game in 2008.