Urban Sociology of Metropolitan Zoning Variance Appeal Bond Requirements and Small Landlord Abandonment in Nairobi's Tenement Districts: A Regression Discontinuity Analysis of Bond Thresholds

Zoning variance appeal bonds in Nairobi's tenement districts are set at fixed monetary thresholds, and small landlords whose holdings fall just below a threshold are widely presumed to abandon improvement appeals rather than post the bond. Testing that presumption with a regression discontinuity design requires a bond threshold that sorts landlords sharply, yet the operating characteristics of such a design under realistic clustering of tenement compounds have not been characterised. 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 discontinuity at 80 per cent power, a requirement that exceeds the 32-cluster ceiling examined here. The contribution is a bounded statement about what a threshold-based study of landlord abandonment can and cannot identify, and a warning that the bond threshold most likely to be studied is also the one least likely to be estimated with adequate precision.