Abstract
Gender gaps in ?nancial literacy are pervasive and persistent. While most studies explore why women know less, these gaps might also re?ect differential behavior in providing responses in surveys. Women might be more likely to be uncertain, or men might be more likely to choose an answer when uncertain, while women might tend to opt for “I do not know”, leading to imprecise measures of the gender gap in ?nancial literacy. We test for the effectiveness of three interventions to reduce the frequency of “I do not know”, in a randomized control trial online survey administered to 6,000 participants. The standard survey, our control group, includes the possibility of answering “I do not know”. The three treatment arms exclude the “I do not know” answer, offer incentives for correct answers or inform survey takers of the existing gender gap in choosing “I do not know”. All interventions are very effective in reducing the frequency of “I do not know”. The information is most effective for women, while the incentives are most effective for men. As regards gender gaps, only the provision of information significantly reduces the gender gap in choosing “I do not know”, as well as the gender gap in ?nancial literacy.