The impact of improved export quality on urban green total factor productivity.

Rapid urbanisation has intensified the challenge for cities to balance economic growth with environmental sustainability. This study examines how higher export quality influences urban green total factor productivity (GTFP), using panel data from 120 Chinese cities (2011–2021). Employing a slack-based measure (SBM) model and two-way fixed effects estimations with robustness checks, the results show that a 1% increase in export quality is associated with an approximate 0.03% improvement in GTFP. The effect is linear and robust across alternative specifications. Further analyses reveal that the positive impact of export quality is contingent on complementary factors: green innovation and industrial upgrading provide steady reinforcement, while digital innovation exerts the strongest amplifying effect, and market openness facilitates international spillovers. Heterogeneity tests indicate that large and coastal cities benefit more strongly than inland or smaller cities. These findings contribute to the trade–environment literature by identifying export quality as a distinct driver of urban green productivity. Policy implications highlight the need to prioritise digital innovation, support green R&D, and deepen trade liberalisation to ensure that export upgrading translates into sustainable urban growth.