Does Settling Trade in National Currency Stabilize the Domestic Currencies? Nonlinear, Asymmetric, and Horizon-Dependent Evidence from Developing Economies

[Purpose] This study asks whether settling international trade in the national currency enhances exchange rate stability in India, and whether the relationship is nonlinear, asymmetric, and horizon-dependent. Motivated by the Reserve Bank of India’s 2022 framework for international trade settlement in rupees and the broader fragmentation of the dollar-centric monetary order, it addresses a gap left by linear, mean-based studies. [Design/methodology/approach] Using monthly data from April 2002 to September 2025 (282 observations), the study combines maximal-overlap wavelet decomposition with quantile-on-quantile regression (WQQR) to estimate how a standardized National Currency Trade Settlement Index (NCTSI), a constructed proxy, relates to INR/USD exchange rate volatility (the inverse of stability) across short-, medium-, and long-run horizons and across the full distribution of both variables. [Findings] The aggregate association is modestly negative, but this masks pronounced heterogeneity. Over long horizons, national-currency settlement is significantly and negatively associated with volatility across most of the distribution, with the association strongest in high-volatility (turbulent) regimes; over medium horizons, it is weak and occasionally positive; and over short horizons, it is statistically negligible. The patterns are robust to alternative volatility measures, an alternative wavelet basis, and a post-2022 sub-sample that isolates the rupee-settlement framework era. [Implications] The results support an invoicing- and settlement-currency interpretation in which reduced reliance on a vehicle currency dampens imported volatility only gradually and most powerfully when external pressure is acute. For policymakers, national-currency settlement operates over long rather than short horizons (conditional on the proxy used), complementing reserves and intervention during periods of external stress rather than substituting for them. [Originality/value] The paper provides, to our knowledge, among the first horizon- and regime-explicit assessments of the settlement-stability nexus for the Indian rupee, extending the invoicing- and vehicle-currency literatures to the volatility margin for a major emerging economy.