Is distance a good proxy for transport costs? The case of competing transport modes

In this paper, we analyze separately the determinants of maritime transport and road transport costs for Spanish exports to Poland and Turkey (markets for which maritime and road transport are competing modes) and investigate the different effects of these costs on international trade. First, we investigate the extent to which maritime and road transport costs depend on different factors such as unit values, distances, transport conditions, service structures, and service quality. Second, we analyze the relative importance of road and maritime transport costs in comparison with distance measures as determinants of trade flows. The main results of this investigation indicate that real distance is not a good proxy for transportation costs and identify the central variables influencing road and maritime transportation costs: for both modes, transport conditions are strong determinants, whereas efficiency and service quality are more important for maritime transport costs, and geographical distance is more important for road transport. Road and maritime transport costs are central explanatory factors of exports and they seem to deter trade to a greater extent than road or maritime transit time when endogeneity is considered.