Researchers collected 12,607 discarded cigarette packs from 126 randomly selected basic geostatistical areas across 11 Mexican cities in early 2023 and classified them by packaging compliance, brand legality and presence of the tax code. The illicit share was 18.2% overall, and among the eight cities also surveyed in 2017 it rose from 8.5% to 20.4% (p<0.001). City-level estimates ranged from below 1% to 43.4%, with divergent trajectories across cities.
Why it is interesting: One of the few longitudinal measures of illicit cigarette supply in a middle-income country, bearing on how far tax-based tobacco control is offset by the untaxed market.