Modal and Territorial Concentration in Import Logistics: Assessing Disruption Exposure Using Customs Revenue Data

Background: Understanding how logistics structure affects fiscal performance and exposure to disruption is critical in import-dependent economies. This study examines the concentration of Ecuador’s import logistics system using customs revenue as an operational–fiscal proxy. Methods: The analysis uses 2023–2024 customs revenue data to evaluate modal and territorial concentration through the Herfindahl–Hirschman Index (HHI). Scenario-based stress tests are applied to assess sensitivity to redistribution and disruption shocks. Results: Results reveal a high dependence on maritime transport and a dominant customs district, with the Guayaquil–Maritime node accounting for most revenue. HHI values confirm strong concentration patterns. Scenario analysis shows that even moderate disruptions in dominant nodes generate disproportionate fiscal impacts, while limited modal diversification slightly reduces vulnerability. Conclusions: The findings indicate that logistics concentration constitutes a structural source of fiscal exposure. The study contributes by framing customs revenue as an integrated proxy linking logistics structure and vulnerability. However, results should be interpreted cautiously due to the short-term dataset, static analysis, and absence of behavioral responses.