The relationship between transhipment incidence and throughput volatility in North European and Mediterranean container ports

Extant literature echoes that ports with a high transhipment share (T/S), and thus a high dependency on sea-sea transhipment or T/S flows, are vulnerable. It is less clear whether the vulnerability of T/S oriented container ports leads to more throughput volatility compared to gateway ports (i.e. inland-bound cargo) or ports with a mixed cargo base (i.e. T/S and gateway flows). In this perspective, throughput volatility, which denotes the variability or the dispersion of the cargo throughput in a port throughout a given period, is of great concern to port actors. This paper examines the relationship between throughput volatility in North European and Mediterranean container ports and the sea-sea transhipment incidence/dependency of these ports. First, we group a large sample of North European and Mediterranean ports in transhipment dependency classes ranging from transhipment ports over mixed ports to gateway ports. Second, we calculate the container throughput volatility between 1990 and 2016 based on two volatility measures. Third, we analyse the relationship between these volatility measures and transhipment incidence. Finally, we compare the results per port group (in terms of transhipment incidence level). The statistical test results show that throughput volatility is much higher for transhipment hubs then for other container ports. This paper also points to some regional market-related elements that explain the observed differences in throughput volatility between port groups. This study can help port planners, managing bodies of ports and terminal operators in their decision-making in the field of container port development and commercial strategies