Campaign Spending Effectiveness
What the research actually says about whether money wins elections, the law of diminishing returns, and when spending matters most.
Does Money Win Elections?
The relationship between campaign spending and electoral success is one of the most studied questions in political science, and the answer is more nuanced than either side of the debate suggests. Yes, candidates who raise more money win more often, roughly 90% of US House races are won by the better-funded candidate. But correlation is not causation. Donors give to candidates they expect to win, so the money follows the frontrunner as much as the frontrunner is created by the money.
The most rigorous studies separate cause from correlation. Political scientist Gary Jacobson's classic research found that challenger spending has a much larger effect than incumbent spending. A dollar spent by a challenger goes further because it buys name recognition and viability that the incumbent already has. Once voters know both candidates, additional spending shows sharply diminishing returns.
