Individual Mobility and Public Transport Subsidies

Politicians around the world are looking for ways to reduce the negative externalities of the transport sector. Subsidization of public transport is a popular remedy, but evidence on the associated causal effects remains scant. Based on a randomized controlled trial that tracks mobility behavior continuously via a mobile app, this study provides causal evidence on how individuals modify their mobility patterns when provided with temporary cost-free access to public transport. We further explore whether such access induces enduring shifts in mobility behavior after the reinstatement of regular fares. We randomly provide roughly half of our around 420 participants - whose selection targeted car users - with a one-month public transport ticket for their local area, and %Leveraging monitor travel behavior across all modes over three months. We find a statistically significant average increase of about two trips per month using public transport during the subsidization period. The rise in public transport utilization, however, is not paralleled by a reduction in car usage, nor does it yield a persistent alteration in mobility behavior in the subsequent month after the ticket expires.