Community matters: Heterogeneous impacts of a sanitation intervention

Abstract

Sanitation is at the heart of public health policies in most of the developing world, where around 85% of the population still lack access to safe sanitation. We study the effectiveness of a widely adopted participatory community-level information intervention aimed at improving sanitation. Results from a randomized controlled trial, implemented at scale in rural Nigeria, reveal stark heterogeneity in impacts: the intervention has immediate, strong and lasting effects on sanitation practices in less wealthy communities, realized through increased sanitation investments. In contrast, we find no evidence of impacts among wealthier communities. This suggests that a targeted implementation of CLTS may increase its effectiveness in improving sanitation. Our findings can be replicated in other contexts, using microdata from evaluations of similar interventions.

Keywords: Community intervention; Nigeria; Randomized controlled trial; Sanitation.

Fig. 1

CLTS impacts on OD by community wealth quartile. Notes: The figure displays estimated confidence intervals for CLTS treatment effects by community wealth quartiles. Household controls are: age, gender, education attainment and employment status of the household head; household size; whether the household has at least one child below age 6; household wealth asset score; and whether farming is the household’s main economic activity. Standard errors are clustered at the community level..

Fig. 2

Dynamics of CLTS treatment effects on OD and toilet ownership. Notes: Graphs plot the point estimates and 95% confidence intervals for CLTS impacts on OD (left) and toilet ownership (right) by follow-up survey wave and community wealth. FU 1, 2 and 3 refer to measurements obtained from followup survey waves conducted 8, 24 and 32 months after baseline. Household controls are: age, gender, education attainment and employment status of the household head; household size; whether the household has at least one child below age 6; household wealth asset score; and whether farming is the household’s main economic activity. Robust standard errors are clustered at the community level..

Fig. 3

CLTS targeting in Nigeria. Notes: The map depicts the targeting map based on quartiles of the percentage of rural communities per region with wealth below the Nigerian median of community wealth. Community wealth is constructed using the DHS asset ownership list discussed in detail in Online Appendix F. Areas marked in darker shades depict regions in the lowest quartile of the Nigerian distribution of rural community wealth, i.e. those with the largest fraction of less wealthy rural communities. Based on our CLTS impact estimates by community wealth, CLTS should first prioritize these regions (where 97% or more communities have below median wealth), then those in the second quartile (where 68 to 97% of rural communities are less wealthy), and so forth. Source: Own calculations based on DHS Nigeria 2013..