[OC] Letter-grade flow for 775 LA County restaurants tracked across one paid health re-inspection cycle (2017–2026)

Source: Los Angeles County Department of Public Health, public restaurant inspection records, 2017–2026. Data portal: [https://environment.lacounty.gov/eh/restaurants/](https://environment.lacounty.gov/eh/restaurants/)

Tool: Python (pandas, matplotlib). Custom Bezier-band Sankey, no third-party Sankey library.

Methodology: 775 LA County restaurants where an unannounced routine inspection scoring below 90 was followed by a paid Owner-Initiated Re-Inspection (RI) — which is scheduled by the operator at a date and time of their choosing — and then by another unannounced routine inspection. Letter grades use standard LA County thresholds (A ≥ 90, B 80–89, C 70–79, F < 70). Median lag from the RI to the next unannounced inspection: 324 days. Compliance and complaint inspections excluded; non-restaurant facilities (markets, schools, etc.) excluded.

Neat! Seems like surprise inspections are very effective at changing behavior.