Rural Sociology of Village Cooperative Audit Committee Rotation Stagger and Member Deposit Withdrawal Timing in Rwandan Savings Cooperatives: A Bunching Estimation of Tenure Stagger Thresholds

Village savings cooperatives in Rwanda rotate audit committee members on staggered tenures, and members time deposit withdrawals around the moments when those tenures turn over. the present analysis treats the tenure stagger as a threshold that members can observe and respond to, and asks whether withdrawal timing bunches at the stagger boundary. Because no observational data are available, the paper develops a design-based characterisation of a bunching estimator applied to a before-after-control-impact (BACI) design with a declared variance structure: between-cluster SD = 6.0, residual SD = 4.5, and intraclass correlation = 0.64. Power was estimated across 2000 replications per design cell for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points. The design requires 56 clusters to detect a 5-percentage-point effect at 80% power. The tenure stagger is a sociologically meaningful threshold rather than a nuisance feature of cooperative governance, and that bunching estimation at that threshold offers a defensible way to study how rural members read institutional rotation as a signal about deposit safety. The contribution is a methodological and conceptual framework for treating audit committee rotation as a behavioural threshold in village cooperative finance.