  Measures to reduce transport-related greenhouse gas emissions are of great
importance to policy-makers. A recent example is the nationwide KlimaTicket in
Austria, a country with a relatively high share of transport-related emissions.
The cheap yearly season ticket introduced in October 2021 allows unlimited
access to Austria's public transport network. Using the synthetic control and
synthetic difference-in-differences methods, I assess the causal effect of this
policy on public transport demand by constructing a data-driven counterfactual
out of European railway companies to mimic the number of passengers of the
Austrian Federal Railways without the KlimaTicket. The results indicate public
transport demand grew slightly faster in Austria, i.e., 3.3 or 6.8 percentage
points, depending on the method, than it would have in the absence of the
KlimaTicket. However, the growth effect after the COVID-19 pandemic appears
only statistically significant when applying the synthetic control method, and
the positive effect on public transport demand growth disappears in 2022.
