Source: UNCTAD.
The hierarchy of ports is often measured by the amount of traffic they respectively handle, with larger ports expected to rank higher. Still, the ordering of the ports also reveals another dimension to this hierarchy, which is the level of concentration. A hierarchy is usually not uniformly distributed; as ports grow more important, the benefits are commonly not linear. They accrue to a small number of ports that gain primacy. For instance, the top 10 container ports accounted for 32.8% of the global container throughput in 2023, underlining a very high level of concentration. Together, the top 50 container ports account for 64.8% of global throughput.
A similar pattern applies to the liner shipping connectivity index (LSCI), but with a lower level of concentration. Still, the top 50 ports account for 48.2% of the total connectivity.