Using visual stimuli to promote healthy snack choices among children.

Most interventions against obesity use information to persuade people to change their behavior, with moderate results. Because eating involves automatic routines, new approaches have emerged appealing to non-reflective cognitive processes. Through a randomized controlled trial, we evaluated the impact of visual stimuli (positive and negative) on children's snack-choices at school. Results showed that the negative stimulus had no effect, while the positive stimulus increased the probability among girls of choosing a healthy snack. We also found that children with excess weight had a larger baseline probability of choosing the healthy snack than those without. We conclude that happy emojis, used to nudge non-reflective processes, can steer children towards healthy choices.

Participation in and provision of public goods: Does granularity matter?

We use public goods games to experimentally investigate the effect of granularity (i.e., the degree of divisibility of the space of feasible contribution options) on participation (whether individuals contribute or not to the public good) and public goods provision (total contribution to the public good). Our results show that granularity has a significant effect on participation, mainly when coarser granularity eliminates the possibility of small contributions. However, this change in participation does not lead to a significant change in the total provision of the public good. These results are aligned with other experimental field results obtained in the context of donations and fundraising.