Formal intergovernmental arrangements as foundational conditions for territorial coordination: evidence from asymmetric regional governance in Vietnam

Intergovernmental coordination in asymmetric territorial settings often fails despite resource complementarities and policy incentives. Drawing on intergovernmental relations scholarship and New Institutional Economics, this article distinguishes formal coordination arrangements as enabling conditions from policy instruments as potential enhancers, and theorizes the political conditions under which such arrangements form. We examine Vietnam's Red River basin, a unitary one-party setting where administrative decentralization grants provinces considerable discretion while horizontal coordination remains weakly institutionalized. Using PLS-SEM and Necessary Condition Analysis on multi-stakeholder data, we find that formal intergovernmental arrangements are strongly associated with coordination effectiveness and display an empirical necessity-in-degree pattern, whereas policy frameworks do not. Interpreted cautiously, these results indicate threshold-like institutional constraints rather than definitive causal proof. The study clarifies how formal arrangements operate as foundational conditions in asymmetric unitary contexts, specifies the political logic of their formation, and disciplines the scope conditions under which the argument travels.