Comparing the performance of models for wider economic benefits of transport infrastructure: results of a Dutch case study

A case is set up concerning a fictitious Dutch high‐speed railway project involving passenger transport. Direct welfare effects are calculated using a standard transport model. On the basis of the case description and the direct effects, five models calculate total welfare effects and wider (indirect) economic benefits. The results of these models are compared. In very broad terms, differences in results can be explained, but on a more detailed level, differences remain that are hard to explain. We also find that large differences in results are caused by differences in the way direct welfare effects are calculated, instead of by differences in wider economic benefits. This suggests that it pays a lot more to focus on understanding and improving direct effect calculations than to try and perfectly quantify wider economic benefits.