Revealed and stated preferences for reliable commuter rail in Norway

We study the effect of travel time reliability on passenger demand using a rich data set on period tickets and train delays over time for commuter trips in the Oslo capital region in Norway. We estimate the relationship between delays and demand using origin-destination fixed effects, which controls for any unobserved time-invariant heterogeneity across stations. The results show a negative effect of delays on demand, but smaller than the effect implied by stated preferences. As a possible explanation for this, we consider a reverse causal relationship, where high demand causes passenger crowding which again results in more delays. Splitting the sample into trips that start at crowded stations within the city-zone and trips that do not, we find evidence indicating that crowding is biasing the estimates towards zero.