This paper seeks to extend the PLANET model to allow for an endogenous influence of transport sector outcomes on the economy. To this end, we embed the PLANET data on freight and household transport for 2003 into a static CGE model of the Belgian economy. Households use transport for commuting and leisure transport, while production sectors use freight as an input. We allow for important feedback effects on generalized transport costs through congestion. To illustrate the model, we contrast the effects of a kilometre charge on freight only and a charge that targets household transport as well.
In network industries the market reform that is being pursued by national and supranational authorities should lead to an improvement of efficiency, which spills over into a beneficial macroeconomic impact. This paper presents two alternative simulations of the potential impact in Belgium. These simulations give very different outcomes, but are still complementary. A macroeconometric approach seems to be more realistic in the short and mid term because it has been built up from observed behavioural relationships. A general-equilibrium approach gives rise to drawing some lessons about the conditions that make the impact more pronounced in the long term.