Urban land-title regularization waves and informal settlement demolition exposure in Nairobi wards: a difference-in-differences estimation of titling-eligibility thresholds

Land-title regularization programmes in Nairobi have been justified as a means of securing tenure for informal settlement residents, yet the same wards that receive titling interventions also experience demolition. Because no observational data are available, the study characterises the operating characteristics of a before-after-control-impact (BACI) design under a declared variance structure (between-cluster SD = 6.0, residual SD = 4.5, 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 analysis indicates that 54 clusters are required to detect a 5-percentage-point effect at 80% power. The framework proposes that eligibility thresholds create a discontinuity in demolition exposure that can be identified through a difference-in-differences specification, and it derives the minimum detectable effect curve for the BACI interaction. The contribution is methodological: it establishes the design parameters under which titling-threshold effects on demolition can be reliably estimated, and it specifies the conditions under which the BACI estimator is informative for urban land policy evaluation.