Municipal fire-risk insurance premium zoning creates discrete jumps in the cost of formal workshop space at risk-class boundaries. The analysis is a replication-based evaluation of the before-after-control-impact estimator, not an observational study: no workshop, firm or insurance data are used or claimed. Under between-cluster SD = 6.0, residual SD = 4.5 and intraclass correlation = 0.64, power was estimated across 2000 design cells for cluster counts of 8, 16, 24 and 32 and effects of 3, 5 and 8 percentage points. The design requires 54 clusters to detect a 5-percentage-point relocation effect at 80% power. Premium-zone boundaries are a plausible but statistically demanding identification strategy for informal-sector relocation, and that the intraclass correlation of 0.64 is the binding constraint on what corridor-level studies can credibly claim.
No takes yet. Share an insight, caveat, or question.
Kamau-Mwangi et al. (2026) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: