Most development practitioners would list engaging communities in the provision of public services among best practices for improving access. However, whether community participation enhances provision and use of public services relative to a non-participatory approach is largely unknown because few studies compare impacts when the same public service intervention is implemented with and without community participation. This field experiment compares three approaches to providing safe water in rural Bangladesh. Delegating decisions to the community increases use of safe water by about 80% relative to a top-down provider making the same decisions but only when the approach to delegating decisions limits elite influence.

Development practitioners have long advocated for targeted beneficiary communities to participate in decision-making about how to provide local public goods and services. However, community participation in decision-making may have disadvantages as well as benefits, and the balance between the benefits and disadvantages may vary across different decision- making processes, interventions, and contexts. Previous studies of community participation in decision-making indeed report mixed results, but the underlying reasons for this remain uncertain. This study demonstrates that context matters. We investigate the heterogeneity of impacts in a field experiment conducted in two regions of rural Bangladesh. The experiment randomly assigns different decision-making processes to villages that receive otherwise identical interventions in the form of a program to increase access to safe drinking water. We show that a deliberative, consensus-based approach to community participation in decision- making has strongly heterogeneous effects compared to either a top-down approach or community decision-making without rules about how decisions are made. The consensus- based process doubles the program's impact in one region but barely increases it in the other. We  use  machine learning to  identify the  baseline  characteristics  and mechanisms that correlate most strongly with impact. The results suggest that the consensus-based process yields better outcomes when there is more at stake: specifically, when the community has fewer pre-existing safe sources of drinking water and thus more to gain from the intervention. The results are consistent with the view that inclusive participatory approaches to decision- making can increase program impacts but fully engaging in these processes is costly. When less  is  at  stake,  communities  may  not  fully  engage, and  the  advantages  of  inclusive participatory decision-making may not be realized.

Development projects that set out to provide local public goods and services almost universally require communities to contribute collectively towards project costs. But despite the ubiquity of such requirements, we know little with certainty about their consequences, including whether consequences differ when communities contribute in cash or labour. Using a randomized experiment, we evaluate how requiring communities to contribute affects the impact of projects that aim to provide safe drinking water wells in rural Bangladesh. Cash contribution requirements strongly reduce take-up and impact relative to a contribution waiver. Labour contribution requirements with similar value if priced at the market wage do not, most likely because most households value their time below the market wage. These results suggest that in poor rural areas, where the monetary value of time is low, projects that require contributions may realize substantial welfare gains by replacing cash contribution requirements with labour contribution requirements. However, imposing any contribution requirement increases coordination and monitoring costs. After accounting for these costs,  requiring  communities to contribute decreases cost-effectiveness, undermining a central rationale for imposing such requirements.

Growth and development depend on the sustainable provision of infrastructure. However, infrastructure is woefully underprovided in much of the developing world, and in many cases falls rapidly into disrepair. The problem is particularly acute in poor and  remote  rural  areas,  where  responsibility  for  maintenance  and  repair  of infrastructure largely lies with communities. A common policy response is to require beneficiaries  to  participate  in  the  design  or  financing  of  infrastructure.  Such participation requirements intend to create “buy-in” or a sense of ownership, thereby increasing the likelihood of maintenance and repair, but they also impose additional costs on poor communities. Are these costs justified? We assemble 15 years of data from more than 600 wells constructed in 259 villages in rural Bangladesh and exploit experimental variation in community participation in project implementation to show that participation can increase sustainability.

Access to safe drinking water in rural Bangladesh remains a perpetual challenge. Most households are exposed to either arsenic or faecal bacteria in their primary source of drinking water, usually a tubewell. Improving tubewell cleaning and maintenance practices might reduce exposure to faecal contamination at a potentially low cost, but whether current cleaning and maintenance practices are effective remains uncertain, as does the extent to which best practice approaches might improve water quality. We used a randomized experiment to evaluate how effectively three approaches to cleaning a tubewell improved water quality, measured by total coliforms and E. coli. The three approaches comprise the caretaker's usual standard of care and two best-practice approaches. One best-practice approach, disinfecting the well with a weak chlorine solution, consistently improved water quality. However, when caretakers cleaned the wells themselves, they followed few of the steps involved in the best-practice approaches, and water quality declined rather than improved, although the estimated declines are not consistently statistically significant. The results suggest that, while improvements to cleaning and maintenance practices might help reduce exposure to faecal contamination in drinking water in rural Bangladesh, achieving widespread adoption of more effective practices would require significant behavioural change.

Progress on improving access to safe drinking water is glacial, and existing strategies for improving access have met with only limited success. We consider an often neglected dimension of water infrastructure provision: cleaning. We randomly assigned caretakers of community wells to participate in a one-off training workshop about how to clean wells. Thirteen to seventeen months later, wells with caretakers assigned to receiving training have negligible rates of contamination with Escherichia coli and almost half the rates of contamination with any coliform bacteria, compared to control wells whose caretakers did not receive training. We estimate that the cost of preventing exposure to coliform bacteria in drinking water is US$0.88 per person and that if scaled up, each US$2034 spent on the intervention could avoid the death of a child. The results suggest that researchers and policy-makers who wish to increase access to safe drinking water should pay more attention to the unglamorous but important topic of cleaning.