A critical mass analysis of community-based financing of water services in rural Kenya

Critical mass dynamics have been widely used to explain the initiation and spread of collective behaviours, from protests and political representation, through to vaccinations and adoption of new technologies. For the first time, this study applies critical mass theory to community waterpoint financial contributions in rural sub-Saharan Africa. The presence of critical mass points, cooperative equilibria and self-reinforcing growth dynamics is empirically evaluated through assessment of multi-decadal waterpoint financial records from rural Kenya, comprising 43,020 household payments over a 26 year period. An examination of month-to-month changes in user contribution rates and financial record continuity suggests contribution levels remain relatively stable once more than 60% of water users are paying. Revenue collection systems tend to become unstable and are prone to collapse during the wet season if user contributions drop below a 60% threshold, but appear to be more resilient in dry season with evidence of self-reinforcing growth dynamics when 40–60% of users contribute. Results reveal that some communities are able to sustain their waterpoint over a long period of time even if a moderate proportion of users do not contribute financially. The analysis also highlights the influence of climate patterns on community-based financing, and the fragility of collective behaviours during wetter periods. Further investigation is needed to assess what dynamics emerge in a more representative sample of waterpoints, particularly in the first few years after installation when failures commonly occur.