Perceived Tariff Policy Uncertainty and Logistics Cost Pressure: The Mediating Role of Supply Chain Adjustment in Vietnam

This study examines the relationship between perceived tariff policy uncertainty (TU), supply chain adjustment intensity (SCA), and logistics cost pressure (LCP) among firms engaged in seaborne import and export activities in Vietnam. Drawing on transaction cost economics, real options theory, and the dynamic capabilities perspective, the study proposes that tariff policy uncertainty affects logistics cost pressure both directly and indirectly through firms’ supply chain adjustments. Data were collected from 320 valid firm-level survey responses across three regions of Vietnam and analyzed using partial least squares structural equation modelling (PLS-SEM). TU and LCP were specified as reflective constructs, whereas SCA was modelled formatively. The results show that TU is positively associated with SCA and LCP, while SCA is positively associated with LCP. The indirect effect of TU on LCP through SCA is also positive and significant, indicating complementary partial mediation. The model explains 33.7% of the variance in SCA and 42.0% in LCP and demonstrates positive out-of-sample predictive relevance. The findings suggest that tariff uncertainty generates logistics cost pressure not only through uncertainty itself but also through the organizational costs associated with supply chain reconfiguration. The study contributes to the trade-policy and logistics literature by identifying supply chain adjustment as an important transmission mechanism in an emerging-market context.