Municipal solid-waste collection fee tiering and informal waste picker organizational density in Accra zonal councils: a boundary-discontinuity estimation of billing-zone thresholds

Municipal solid-waste fee tiering in Accra assigns households to billing zones whose boundaries cut across the settlement patterns of informal waste pickers, yet no study has isolated the effect of crossing a fee threshold on the organisational density of picker associations. The estimand is the jump in picker organisational density at the billing-zone threshold, identified from households and associations whose locations are arbitrarily close to the boundary on either side. Because the design is not yet executed, the paper reports a replication-based evaluation of the before-after-control-impact estimator under a declared variance structure: between-cluster standard deviation of 6.0, residual standard deviation of 4.5, and intraclass correlation of 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 per cent power, a requirement that exceeds the 32-cluster maximum examined and that reframes the zonal council as the binding sampling constraint. The contribution is a pre-field design protocol that specifies the estimand, the identification assumptions and the power envelope for a study of fee-tier effects on informal-waste organisation in Accra.