News & Learning

Nudging a Habit: Evidence from a handwashing experiment in Vietnamese primary schools

Washing hands with soap helps prevent diarrhea, respiratory diseases and soil-transmitted helminth infections. In Vietnam, handwashing with soap (HWWS) is taught to all first-grade students as part of national curriculum through 1-hour sessions, titled “Body hygiene”.  Still, most children—like most adults^[1]—don’t wash their hands after defecating.  However, a recent study found that simple “nudges” significantly increased handwashing after latrine visits at two schools in Bangladesh (Dreibelbis et al, 2016). While Chase and Do (2012) found that a large scale handwashing campaign in Vietnam had virtually no impact on the frequency of handwashing among “caregivers” (i.e. mothers with small children), the Bangladeshi study reported that the percentage of children practicing HWWS after a visit to the school latrine increased from 4% to 74%.

Given the results of the Bangladeshi study, we sought to answer five questions:

1. Do nudges work only in a specific social/cultural setting or are the results more universal?
2. Is there a novelty effect of the nudge, i.e. does the effect decline over time
3. After a long time with nudges, will behavior last if we remove the nudges, i.e. have we created a habit?
4. Are we sure that we don’t just observe a Hawthorne effect, i.e. do the children wash their hands only because they are observed?
5. Do children fail to wash their hands with soap after latrine visits because there is no convenient place to wash the hands and there is no soap?

[1] Freeman et al (2014) estimated that only 19% of the world population washes hands with soap after contact with excreta.

For the full study and results, see here: Nudging A Habit Handwashing In Schools