Hidden Costs of Floating FX: Lessons from Indonesia and Vietnam
A comparative analysis of Indonesia’s flexible exchange rate regime and Vietnam’s managed peg reveals stark differences in inflation stability. While Vietnam’s model buffers external shocks, Indonesia’s approach leaves it exposed to capital-flow volatility and dollar dependency.
Divergent Paths to Price Stability
From 2015 to 2024, Vietnam’s managed exchange rate kept core inflation at 2.10% with a standard deviation of 0.90 percentage points, while Indonesia’s flexible regime delivered 2.92% (σ = 0.99). The rupiah’s volatility (CV 6.66%) far exceeded the dong’s (CV 4.17%).
What Drives the Gap
Structural vector autoregression (SVAR) analysis shows that external financial shocks—mainly U.S. Fed policy and exchange-rate pass-through—account for 53.6% of Indonesia’s core inflation variance, versus only 17.2% from its own monetary policy. Vietnam’s central bank, by prioritizing a stable exchange-rate anchor, limits transmission of global shocks and achieves faster policy effects (within two quarters).
The Dollar Constraint
Indonesia’s reliance on capital inflows forces it to shadow Fed rate moves. In June 2026, the rupiah weakened to 18,000 per dollar, triggering a 100-bp emergency hike. Headline inflation remained near 2.9%, but the growth-stability trade-off intensified.
Policy Implications
Vietnam demonstrates that a hybrid approach—managed float plus targeted credit controls—can insulate an economy. For Indonesia, the path forward requires complementing market-based tools with structural measures: deepening domestic bond markets, building digital-payment networks (QRIS, ISO 20022), and reducing commodity dependence. Monetary policy alone cannot overcome the built-in vulnerabilities of a dollar-pegged global system.
