Incentives and Children's Dietary Choices: A Field Experiment in Primary Schools

We conduct a field experiment in 31 primary schools in England to test the effectiveness of different temporary incentive schemes, a standard individual based incentive scheme and a competitive scheme, on increasing the choice and consumption of healthy items at lunchtime. The individual scheme has a weak positive effect that masks significantly differential effects by age whereas all students respond to positively to the competitive scheme. For our sample of interest, the competitive scheme increases choice of healthy items by 33% and consumption of healthy items by 48%, twice and three times as much as in the individual incentive scheme, respectively. The positive effects generally carry over to the week immediately following the treatment but we find little evidence of any effects six months later. Our results show that incentives can work, at least temporarily, to increase healthy eating but that there are large differences in effectiveness between schemes. Furthermore it is important to analyse things at the individual level as average effects appear to be masking significant heterogeneous effects that are predicted by the health literature.