Romney’s strong fundraising and big spending suggest that he and allied groups might finally eliminate Obama’s advertising advantage. But as of the week ending October 14, that has not happened. As the graph below indicates, advertising spending on behalf of Obama continues to outpace spending on behalf of Romney. Obama and allies aired about 5,000 more television ads than Romney and allies last week.
Here is what this means: across all the presidential general election advertising by candidates, parties, and groups, each pro-Obama ad has cost an average of $502 dollars. But each pro-Romney ad has cost an average of $630.
This may also help to explain why Obama has retained an edge in most battleground states. Here is how both campaigns were targeting their ads in the previous week:
Is any of this advertising making a difference? That is the ultimate question and one I will revisit. For the moment, however, there is one study worth noting. The consulting firm Evolving Strategies recently completed a large randomized experiment in which participants saw pro-Romney ads, pro-Obama ads, both, or neither. On the whole, the Obama ads were more effective in persuading weak partisans and undecided voters—even when the Romney ads were shown alongside. Their effect was particularly notable among women.
However, there was a potentially countervailing effect as well: these ads tend to increase the enthusiasm of Republican voters but not Democratic voters, which could translate into additional Republican turnout.
I’ll be back next week to update these numbers.
John Sides is a professor of political science at George Washington University and a founding member of the Monkey Cage.