Blaise OSS
Rat Containerization and Complaint Volume: Did NYC's Mandatory Bin Rollout Causally Reduce Rodent Sightings?
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Findings — showcase-rat-containerization

April 2026 · v3.0.0

Auto-generated from artifacts/reconciled_findings.json. Regenerations are byte-identical when the underlying numbers do not change; edits to this file are overwritten on next run. See MANUSCRIPT.md for the hand-authored narrative.

Headline

BJS staggered DiD ATT = -11.90 Rodent complaints per community district per month (SE = 0.70, 95% CI [-13.28, -10.53], p < .001, N = 5,550).

BJS staggered-DiD: across both cohorts (2023 pilot + 2024 citywide rollout), treated community districts experienced a reduction of 11.9 rodent complaints per CD per month post-treatment (95% CI [-13.3, -10.5]).

Panel

  • Geography: community district (NYC), N = 74 units.
  • Period: 2020-01 → 2026-03, monthly frequency (N = 75 periods).
  • Observations: 5,550 CD-month cells.
  • Total rodent complaints in window: 224,889.
  • Cohort 1 (pilot, 2023-07-01): 9 treated CDs — MANHATTAN 01, MANHATTAN 02, MANHATTAN 03, MANHATTAN 04, MANHATTAN 05, MANHATTAN 06, MANHATTAN 07, MANHATTAN 08, MANHATTAN 09.
  • Cohort 2 (citywide rollout, 2024-11-12): 50 treated CDs across the remaining boroughs.
  • Never-treated controls: 15 irregular districts (airports, parks, cemeteries, geocoding-failure catch-alls).

Cross-estimator agreement

Estimator ATT SE p
TWFE -10.27 1.78 < .001
CS -4.87 2.01 0.015
SA -12.85 2.81 < .001
BJS -11.90 0.70 < .001

All four estimators agree in sign. With staggered adoption (two cohorts), TWFE and BJS no longer coincide mechanically — the spread between TWFE (the naive panel fixed-effects estimate) and the heterogeneity-robust triple (CS, SA, BJS) is itself evidence of treatment-effect heterogeneity between the pilot and the citywide cohort.

Robustness

Check ATT / coef p Reading
Placebo t₀ = 2022-07-01 (BJS) +9.97 < .001 Direction of the placebo tells us whether unobserved pre-trends would produce a spurious effect.
Log-outcome TWFE +0.227 (+25.4%) 0.092 Multiplicative specification: sign preserved, magnitude smaller.
Post-COVID sample (2022-01 →) -6.70 < .001 Isolates the policy window from 2020 lockdown variance.
Manhattan-only controls (BJS) +3.62 0.059 Controls restricted to non-pilot Manhattan CDs; removes outer-borough confounds.

Diagnostics

Diagnostic Value Reading
Parallel-trends joint F F = 4.40, p < .001 Reject flat pre-trends — see HonestDiD sensitivity in §4.6 and Appendix C.
Breusch-Pagan p < .001 Heteroskedastic residuals; cluster-robust SEs mitigate.
TWFE R² 0.802 Within-panel variance absorbed by fixed effects.
Shapiro-Wilk sampled p < .001 Non-normal residuals — count-data feature; large-N CLT applies.

Balance (pre-treatment)

Pre-period mean monthly complaints: 51.1 (treated pooled across both cohorts) vs. 1.6 (never-treated controls). Welch t = 65.52, p < .001, Cohen's d = 1.89. Treated community districts carry higher pre-period complaint rates; the staggered-DiD identifying variation is the change from this elevated baseline vs. the contemporaneous change in the never-treated pool.

Author: Blaise Albis-Burdige. Stable-override generated_at="stable" and hostname="showcase-runner" per .claude/skills/committed-tearsheets.md.