National permitting dataset exposes housing chokepoint

A standardized, nationwide permitting database (60 cities in the new paper) lets researchers measure permit‑approval durations and directly link them to building pace and rents. The new evidence shows permitting time explains a large share (30–43%) of cross‑city differences in project completion, and that permitting has generally slowed since 2000. — If permitting durations are a measurable, substantial driver of slow housing supply, targeted permit‑process reforms become a specific, politically actionable lever to expand supply and reduce housing costs.