to overcome challenges with the estimation of cargo payloads, using detailed information on shipping liner schedules ( Box 2 ) to validate port calls, and applying country-specific information to define port boundaries. Unlike previous studies, we do not need to make assumptions on ballast water or assume cargo weight changes linearly with the ship’s draft. Finally, the results can be replicated transparently by other researchers using data from the UN Global Platform, unlike other studies which are based on proprietary data from commercial data providers that make
Pacific island countries. The algorithm significantly advances estimation techniques of previous studies, particularly by employing ways to overcome challenges with the estimation of cargo payloads, using detailed information on shipping liner schedules to validate port calls, and applying country-specific information to define port boundaries. The approach can complement and help fill gaps in official data, provide early warning signs of turning points in economic activity, and assist policymakers and international organizations to monitor and provide timely responses
the movement of goods across the globe? What are the benefits and challenges of using big data to produce real-time information about trade? In what ways can countries use this source to complement traditional sources of trade statistics? To answer these questions, a team of IMF economists employed a more structured version of the AIS data, containing “port-calls data.” Port-calls data combine ship positions and port boundaries to track the arrival and departure of ships in a port. The economists used Malta-an island state in the European Union, with a population
find a departure, we eliminate the unmatched port call. We find 418 unmatched port calls (less than 1 percent of the sample), which are noted for all types of ships. Stay in the harbor outside reasonable range for trade activity. The third rule eliminates calls of ships that remained in the port boundaries for only a short time (less than five hours) or for too long (more than 60 hours). 7 Available port statistics for Malta indicate that almost 80 percent of cargo vessels stay less than one day, and very few exceed three days (Table 2.12 of National Statistics