This paper analyses the relationship between firms' multi-factor productivity and the effective employment density of the areas where they operate. Quantifying these agglomeration elasticities is of central importance in the evaluation of the wider economic benefits of transport investments. We...

The only significant road pricing scheme in the UK is that introduced by Ken Livingstone in London. But the technology now exists to develop a nationwide scheme of road user charging, with prices to road users varying with the level of congestion in a given area at a given time. The only...

This paper reviews methods that seek to draw causal inference from non-experimental data and shows how they can be applied to undertake ex-post evaluation of transport interventions. In particular, the paper discusses the underlying principles of techniques for treatment effect estimation with...