The Price of Distance: Cannabis Dispensary Access and the Composition of Fatal Crashes

Abstract

This paper investigates whether access to legal marijuana reduces the share of fatal crashes involving alcohol through marijuana-alcohol substitution. Using FARS crash-level data from 2016–2019 for eight illegal states near legal cannabis markets (ID, WY, NE, KS, UT, AZ, MT, NM), I construct a continuous treatment measure: driving time to the nearest legal dispensary. Among 18,430 fatal crashes, I find that a one-unit increase in log driving time is associated with a 2.4 percentage point increase in the probability that a crash involves alcohol (baseline rate: 31.7%). Doubling drive time corresponds to a 1.7 percentage point increase (0.024 $\times$ ln(2) $\approx$ 0.017). Effects are concentrated near legal-state borders (within 200km), consistent with a cross-border purchasing mechanism. Placebo tests on daytime crashes and elderly driver involvement yield null results, supporting the interpretation that access to legal cannabis substitutes for alcohol consumption. These findings suggest that marijuana legalization may generate spillovers by reducing the alcohol-involved share of fatal crashes in prohibition states.