Quantifying wide economic impacts of agglomeration for transport appraisal: existing evidence and future directions

This paper is concerned with the Wider Economic Impacts (WEIs) of transport improvements that arise via scale economies of agglomeration. It reviews the background theory and empirical evidence on agglomeration, explains the link between transport and agglomeration, and describes a three step procedure to appraise agglomeration impacts for transport schemes within Cost Benefit Analysis (CBA). The paper concludes with a set of recommendations for future empirical work on agglomeration and transport appraisal.