使用国际货币基金组织（IMF）PortWatch预测国家级贸易估算

Nowcasting Country-levelTrade Estimates using IMF Serkan Arslanalp, Oliver Exton, Chang Gao, Parisa Kamali, MarioSaraiva, Alessandra Sozzi, and Jasper Verschuur WP/26/99 IMF Working Papersdescribe research inprogress by the author(s) and are published toelicit comments and to encourage debate.The views expressed in IMF Working Papers arethose of the author(s) and do not necessarily 2026MAY IMFWorking Paper Strategy, Policy and ReviewDepartmentand Statistics Department NowcastingCountry-levelTradeEstimatesusing IMF PortWatch Prepared bySerkan Arslanalp, Oliver Exton, Chang Gao, Parisa Kamali, Mario Saraiva, Alessandra Sozzi, andJasper Verschuur* Authorized for distribution byMarco MariniandMichele Ruta IMF Working Papersdescribe research in progress by the author(s) and are published to elicitcomments and to encourage debate.The views expressed in IMF Working Papers are those of the ABSTRACT:This paper develops high frequency trade estimates at the country level by applying nowcastingmethodologies to satellite-based big data on vessel movements sourced from IMF PortWatch. The approachprovides a timely estimate of monthly trade at the country level that can be produced and released within 7working days. The paper validates the nowcasting trade estimates against official data for an initial wave ofcountries representing advanced economies, emerging markets and small island developing states: Brazil, RECOMMENDED CITATION:Arslanalp et al. (2026). Nowcasting country-level trade estimates using IMFPortWatch.IMF Working Paper 26/99. Table of Contents Table of Contents................................................................................................................................................1 2.Overview of nowcasting methodology...................................................................................................6 3.Development of country-level trade estimates......................................................................................8 a. Baseline performance.........................................................................................................................9b. Port review........................................................................................................................................10 ▪i. Deflators.........................................................................................................................................15▪ii. Maritime comparison group...........................................................................................................16 4.Performance of nowcast........................................................................................................................18 a.Assessment of revised results..........................................................................................................18b. Brazil.................................................................................................................................................20c. Jamaica.............................................................................................................................................22d. Japan................................................................................................................................................24e.Samoa..............................................................................................................................................26 5.Cross-comparability of PortWatch estimates......................................................................................31 BOXESBox 1. U.S. Imports amid Elevated Trade Tensions......................................................................................30 FIGURES Figure 1. From Physical Volume to Trade Estimates......................................................................................6 Figure 2. Share of trade in goods transported by sea.....................................................................................9Figure 3. Port of Santos Polygon....................................................................................................................11Figure 4. Brazilian ports and offshore platforms...........................................................................................12Figure 5. Port of Kingston (Jamaica) container trade volumes....................................................................13Figure 6. Port of Kingston PortWatch estimates incorporating netting adjustment..................................13Figure 7. Port Rhoades Export Volumes........................................................................................................14 TABLESTable 1. Baseline assessment table................................................................................................................10Table 2. Summary of adjustments by country..............................................