Effectiveness of interventions to induce waste segregation by households: evidence from a randomized controlled trial in Mozambique

The City Council of Maputo (CMM) and the Japan International Cooperation Agency (JICA) began a pilot project to introduce segregated waste discharge in households and its collection in a suburb of Maputo City, Mozambique, in 2014. After an initial rollout of the program showed low household-level compliance with the new waste segregation requirements, CMM and JICA conducted a randomized control trial (RCT) to evaluate potential measures to induce more cooperation from households. The study was a parallel group comparison with three interventions (i.e., household goods exchange, segregation buckets provision, and periodic home visit instruction). In total, 1000 target households (sample size of 250 households for each group) were randomly allocated out of 1817 eligible households in the target area. The analysis found each applied intervention to be effective, the households with interventions were 7.5-10.6% points more likely to segregate the waste compared with the control group (significant at 1% level), and 267.4-386.1 g/households/2 weeks of target recyclables was incrementally discharged from the intervention groups, while that of the control group was 25.57 g/household/2 weeks (significant at 1-10% levels). However, cost-effectiveness of the pilot project and the applied interventions was low when compared with the other recycling pilot projects attempted in the project.