Unpacking electoral competition: campaign spending, vote distribution and turnout in Chilean mayoral elections

We examine the complex relationship between campaign spending and electoral outcomes in local elections. We focus on (1) how spending influences the distribution of votes across candidates; (2) its impact on voter turnout; and (3) the differential effects of different types of campaign spending. Using the case of Chile’s 2016 mayoral elections, a candidate-level dataset, and linear regression techniques, we estimate the impact of campaign spending on the share and dynamics of votes obtained. The study reveals that an additional investment of 50 cents per voter correlates with an average 5% increase in vote share as a proportion of elegible voters. This increase is attributed to a double effect: mobilizing new voters and attracting support from competitors. The disaggregated analysis shows that radio advertising is especially impactful for campaign dissemination. These results enrich the literature on electoral strategies, campaign finance dynamics and financing regulations in multi-party systems.