Indigenous Naming-Ceremony Timing and Postpartum Depression Symptom Reporting Among Luo Mothers: A Regression-Discontinuity Estimation of Ritual Status and Disclosure Thresholds

Luo mothers in western Kenya who have not yet completed the naming ceremony (nyuol) occupy an ambiguous ritual status that may suppress the disclosure of postpartum depressive symptoms. The design is evaluated through a replication-based power analysis of the before-after-control-impact estimator, with between-cluster SD = 6.0, residual SD = 4.5, and intraclass correlation = 0.64. Power was estimated across 2000 design cells spanning cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points. The analysis indicates that 54 clusters are required to detect a 5-percentage-point effect at 80% power. Ritual status operates as a disclosure threshold rather than a direct aetiological factor, and that regression-discontinuity estimation can separate the ceremonial timing effect from the underlying symptom burden. The contribution is a design template for studying how indigenous ritual transitions shape the reporting of psychological distress, together with explicit operating characteristics that bound its interpretation.