  We estimate the causal effect of shared e-scooter services on traffic
accidents by exploiting variation in availability of e-scooter services,
induced by the staggered rollout across 93 cities in six countries.
Police-reported accidents in the average month increased by around 8.2% after
shared e-scooters were introduced. For cities with limited cycling
infrastructure and where mobility relies heavily on cars, estimated effects are
largest. In contrast, no effects are detectable in cities with high bike-lane
density. This heterogeneity suggests that public policy can play a crucial role
in mitigating accidents related to e-scooters and, more generally, to changes
in urban mobility.
