Old is not always better: evidence from five randomized experiments in rural primary schools in China

In recent years, researchers have begun to focus attention on trying to identify systematic factors that cause interventions to have different impacts in different contexts. In this paper, we seek to understand whether the age of principals at schools implementing nutrition-based interventions has an impact on program outcomes. To explore the relative effectiveness of younger and older school principals, we use data from five large-scale, nutrition-related randomized controlled trials (RCTs) involving 12,595 primary school students in 336 schools in rural China. Our results, using two age cut-offs for distinguishing young principals from old ones, indicate that improvements in the health and nutrition outcomes of students were significantly higher in schools with younger principals than in schools run by older principals (when using a cutoff of 40 years old). When using a cut-off of 45 years old, the point estimates of the impacts similarly suggest that young principals are more effective, although the results are not significantly significant. The results are similar when we look at the impact of disaggregated interventions in schools managed by young and old principals. The findings are clear that the interventions implemented by older principals are not more effective than those implemented by younger principals.