Competitive Dynamics of BRICS Ocean-Based Exports: Sequential Constant Market Share and Revealed Comparative Advantage Evidence, 2013-2024

Resumen

Ocean-based trade now forms a significant part of economic competition among the BRICS nations: Brazil, Russia, India, China and South Africa. Yet the sector-level forces behind their shifting global market shares have not been examined systematically. This paper applies a sequential Constant Market Share (CMS) analysis, combined with Revealed Comparative Advantage (RCA) and Revealed Symmetric Comparative Advantage (RSCA) indices, to annual bilateral ocean trade data from UNCTADstat across five commodity categories, 2013 to 2024. The sequential approach chains consecutive year-pair decompositions, splitting total market share change into competitiveness, commodity composition and commodity adaptation effects.
China recorded the largest cumulative gain, at 4.30 percentage points, driven almost entirely by the market share effect (+4.47). A commodity composition drag partly offset this, pointing to early over-specialisation in slower-growing ocean segments. India and Russia each gained close to a quarter of a percentage point through competitiveness alone. Russia's advantage sat in marine fisheries, where RCA rose from 3.29 to 4.43, while India's centred on ships and port equipment, where RCA has stayed above 1.0 since 2014. Russia's ocean trade data stopped appearing after 2021, alongside international sanctions, and this gap carries weight of its own. Brazil's position turned marginally positive across the extended window, while South Africa recorded a small cumulative decline. These findings speak to maritime policy, South-South shipping value chains and how BRICS nations are repositioning themselves in global ocean commerce.