Does campaign spending help voters learn about ballot measures?

What happens when a ballot measure becomes an orphan and there are no campaign expenditures for or against the measure? California's Proposition 91 provides one example of such a scenario and offers a rare opportunity to study what voters learn about a ballot measure in the absence of a campaign. Using an election survey, I assess what voters exiting the polling booth learned about Proposition 91 and compare it to what they learned about several other measures on the same ballot. My results suggest that even without a campaign, a large majority of voters still know a fact about Proposition 91. I also find that campaigns can greatly increase knowledge of the facts they choose to emphasize.

► Campaign spending has a limited effect on voters' policy-specific knowledge of ballot measures.
► A majority of voters know at least one fact about ballot measures, regardless of campaign spending.
► Campaigns can inform voters about the selective facts they choose to emphasize.