Green and Digital Trade Between Viet Nam and Japan Through Technology Specialisation and Supply Chain Concentration

Green and digital goods are central to the energy transition, yet the structure of their trade between Viet Nam and Japan has received little attention. This study aims to show how four established trade indicators, read jointly, distinguish product groups by export specialisation, market complementarity, bilateral trade balance, and sourcing concentration. Using six-digit trade data from the World Integrated Trade Solution (WITS) and UN Comtrade for 2018–2023, it applies the Revealed Comparative Advantage index (RCA), the Trade Complementarity Index (TCI), the Grubel–Lloyd index (GL), and the Herfindahl–Hirschman Index (HHI) of Japan’s import sources to six groups: low-carbon technology goods, environmental goods, lithium-ion battery supply chain goods, industrial robots, semiconductors, and 3D printing goods. The configurations differ by group. In industrial robots, both countries show revealed specialisation, and gross bilateral trade is almost balanced. In environmental goods, Viet Nam’s export structure moved closer to Japanese import demand before revealed specialisation emerged. In semiconductors, Vietnamese specialisation coexists with unbalanced bilateral trade. Product-level checks show that the group-level HHI understates the concentration in battery goods, whereas the semiconductor result depends on the treatment of “Other Asia, n.e.s.”. The contribution is configurational: the indicator combinations show where evidence on value added, capability formation, and dependence is most needed.