Can incentives change children’s lunch choices and develop healthy habits?

By Jonathan James, Max Weber Fellow 2011-2012

As a result of the rising level of childhood obesity children’s diet has become a major concern for policymakers in most developed countries.

According to the World Health Organization (2002) nutrition plays a significant role in four of the ten leading risks behind disease burdens. Still, poor diet habits are widespread and form very early on in life.

How to get children to choose healthy options, and eat fruit and vegetables, is therefore an important policy concern not just for the short term health benefits that eating these items bring but also because of the early formation of habits.

Therefore I, along with two colleagues, Michele Belot (Oxford) and Patrick Nolen (Essex), conducted a randomised field experiment which used incentives to encourage children to make healthy choices at lunch.

We ran this experiment in 46 primary schools in eleven different local authorities all over England, from Cumbria in the north west of England (which borders with Scotland) down to Brighton (on the South Coast).

In most schools we ran the experiment in two classes, one from year 2, (with children aged around 6), and year 5 (aged around 9).

We provided temporary incentives, in the form of stickers, stationery and small toys (e.g. yoyos), to see if they could trigger long lasting changes in children’s nutritional choices at lunch, specifically for boys and children from lower socio-economic status.

The set of interventions we proposed were inspired by recent findings in economics and psychology (e.g. Charness and Gneezy (2009)) that have shown that providing short term incentives can have long lasting effects on behaviour, that is, by providing incentives temporarily, habits can be developed and sustained when the incentives are removed.

Our schools were randomly split into three groups.We tested two different treatments.

First, we adopted a piece rate scheme. Children were rewarded each day for choosing a fruit or vegetable at lunch and monitored for how much they consumed. If they made a healthy choice they were given a sticker. At the end of the week if they had received four or more stickers they got to choose an extra reward from the reward box.

Our second treatment tests a competitive rewarding scheme. Each pupil is rewarded daily in the same way as the piece rate scheme; however, at the end of the week they got a prize only if they had collected the most stickers in their group, which consisted of three other pupils.

Our final group was a set of control schools. We monitored their choices in the same way. The only difference between the groups was the provision of incentives.

The experiment began in October last year and ran for 6 weeks. The first week just involved monitoring. At the start of the second week incentives were introduced for four weeks. In the sixth and final week we removed the incentives but maintained the monitoring.

We’ll soon know if handing out stickers and toys changed the choices made by children at lunchtime.

We are also planning to return to the schools to monitor the children’s choices in the upcoming summer term, and in September to examine whether we see medium to long run effects, therefore uncovering if short term incentives developed healthy dietary habits.