Institutional spillovers and energy efficiency in maritime transport: Evidence from the EU MRV dataset

Improving energy efficiency in maritime transport is a key pillar of decarbonization policy. While existing studies often focus on individual vessels or aggregate trends, this paper introduces a spatial-institutional perspective to explore how regulatory and operational interdependencies among flag states influence ship-level efficiency. Using vessel-level data from the EU Monitoring, Reporting and Verification (MRV) system, it is applyed a Spatial Durbin Model (SDM) to assess whether improvements in technical efficiency diffuse across ports of registry. Results confirm significant institutional spillover effects: a vessel's efficiency is positively influenced by the performance of ships registered under the same or administratively related flags. Fuel consumption and CO2 emissions are negatively associated with efficiency, while time at sea shows a positive relationship. Counterfactual scenarios indicate that targeted fuel-reduction policies could trigger amplified efficiency gains through institutional multipliers. The findings suggest that registry governance, regulatory alignment, and cooperative mechanisms under frameworks like the EU ETS can enhance sector-wide decarbonization. This study contributes to the literature by introducing a spatial–institutional perspective on maritime energy efficiency, empirically quantifying registry-based spillover effects using vessel-level MRV data, and providing policy-relevant insights for coordinated decarbonization strategies within multilevel transport governance systems.