Urban development-induced demolition of informal market halls and vendor network reconstitution in Lagos: a difference-in-differences estimation of displacement-timing thresholds

The unresolved problem is that demolition schedules are treated in policy as binary events, whereas vendor reconstitution depends on the interval between notice and clearance and on the density of the surrounding vendor ecology. No observational data are used or claimed. Under a declared variance structure with 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 effect sizes of 3, 5 and 8 percentage points.54 clusters are required to detect a 5-percentage-point effect at 80 per cent power, that the minimum detectable effect falls steeply as clusters increase from 8 to 32, and that the estimator's precision is dominated by the intraclass correlation rather than by the number of vendors observed. The contribution is a design framework that reframes displacement timing as a threshold parameter and specifies the cluster counts needed to estimate it credibly.