Replication and Methodological Evaluation of Power-Distribution System Diagnostics for Yield Improvement in Kenya: A Quasi-Experimental Design

{ "background": "Power-distribution system diagnostics are critical for improving agricultural yield in regions with unreliable electricity. Previous studies, predominantly simulation-based, have claimed significant benefits from such interventions, but their methodological rigour and field applicability in sub-Saharan contexts require verification.", "purpose and objectives": "This study aimed to replicate and methodologically evaluate a quasi-experimental design for assessing the impact of power-distribution equipment diagnostics on maize yield. The core objective was to test the robustness of the original diagnostic protocol and its reported yield improvements under controlled field conditions.", "methodology": "A quasi-experimental design was implemented across multiple sites. Treatment groups received the full diagnostic and corrective intervention for power-distribution infrastructure, while control groups received standard maintenance. Yield was measured as tonnes per hectare. The impact was estimated using a difference-in-differences model: Yit = \β0 + \β1 (Treati \× Postt) + \γ Xit + \εᵢₜ, where robust standard errors were clustered at the substation level.", "findings": "The replication found a positive but statistically non-significant yield effect. The point estimate for yield improvement was 0.15 tonnes/ha (95% CI: -0.08, 0.38), contrasting with the originally reported significant gain of 0.35 tonnes/ha. Methodological evaluation identified sensitivity of results to the clustering of standard errors and baseline imbalance in soil quality.", "conclusion": "The purported yield benefits of the diagnostic protocol were not robustly replicated under the study's conditions. The quasi-experimental design, while field-applicable, requires stricter pre-intervention matching on agronomic variables to isolate the effect of electrical diagnostics.", "recommendations": "Future applications of this diagnostic methodology should incorporate pre-intervention soil and water data into the experimental design. Power-distribution interventions should be integrated with broader precision agriculture practices to discern their standalone value.", "key words": "replication study, quasi-experiment, power