Exchange Rate Pass-Through

What Is Exchange Rate Pass-Through?

Exchange rate pass-through (ERPT) is the elasticity that captures how much of a given percentage change in the nominal exchange rate flows through into import prices, producer prices, and ultimately consumer price inflation. A pass-through of 1.0 (complete or full ERPT) implies that a 10% depreciation of the domestic currency raises import prices by exactly 10%. In practice, most advanced economies exhibit incomplete pass-through, typically in the range of 0.1–0.5 at the consumer price level over a 1–2 year horizon, while emerging markets tend to have significantly higher coefficients, often 0.4–0.7 or more.

The mechanism operates in stages. First-stage ERPT affects import prices at the border; second-stage ERPT traces how much of that border price change filters through to retail CPI. The gap between the two stages depends on domestic distribution margins, pricing power of retailers, the currency of invoicing (dominant currency pricing vs. producer currency pricing), and the credibility of the central bank's inflation targeting framework. Economies where trade is invoiced predominantly in US dollars — a phenomenon studied under dominant currency pricing — often exhibit asymmetric ERPT, with depreciations passing through more strongly than appreciations.

Why It Matters for Traders

For macro traders, ERPT is the critical transmission link between FX intervention, monetary policy divergence, and inflation dynamics. A central bank assessing whether a currency depreciation is inflationary — and therefore whether it needs to respond with rate hikes — must estimate ERPT in real time. When ERPT is high and the currency is weakening, the monetary policy reaction function tightens more aggressively, creating positive feedback between FX weakness and rate hikes that can amplify currency moves.

In carry trade analysis, ERPT asymmetry is exploitable: if a funding currency country (low ERPT) depreciates modestly, inflation remains contained and the central bank is unlikely to hike, preserving the carry. By contrast, a high-ERPT target currency country may be forced to hike even when growth is weak, creating adverse macro dynamics for local equity and credit markets.

How to Read and Interpret It

Analysts typically estimate ERPT using vector autoregression (VAR) models or rolling OLS regressions of import price changes on lagged exchange rate changes. Key thresholds to monitor:

• ERPT > 0.5 at consumer level: High — central bank likely to respond to FX weakness with hikes; watch nominal wage growth for second-round effects
• ERPT 0.2–0.5: Moderate — selective response depending on output gap and inflation expectations
• ERPT < 0.2: Low — typical of large, relatively closed economies; FX moves can be tolerated by monetary policy without immediate inflation consequences

The import price index relative to the trade-weighted exchange rate (NEER) over rolling 3- and 12-month windows provides a real-time ERPT estimate practitioners can track without running formal econometric models.

Historical Context

The Bank of England's experience following the Brexit referendum provides a clear empirical case. Sterling fell approximately 15% on a trade-weighted basis between June and October 2016. UK import prices rose roughly 8–10% over the subsequent 12 months, implying a first-stage ERPT of around 0.55–0.65. CPI rose from approximately 0.5% pre-referendum to a peak of 3.1% in November 2017, with the Bank of England estimating that roughly 1.5–2 percentage points of that increase was directly attributable to sterling depreciation — consistent with a second-stage ERPT of approximately 0.15–0.20. The episode highlighted how even a moderate-ERPT economy could see significant inflation consequences from a large, persistent FX shock.

Limitations and Caveats

ERPT is not stable over time or across regimes. Evidence suggests ERPT declined across most advanced economies from the 1990s to 2010s as inflation expectations became better anchored — a phenomenon attributed to the Taylor Rule discipline of inflation targeting central banks. However, in a post-pandemic, higher-inflation regime, ERPT may be reverting to historically higher levels. Additionally, dominant currency pricing means that ERPT for countries invoicing in dollars is asymmetric with respect to bilateral USD moves versus multilateral moves.

What to Watch

• Import price index releases relative to trailing NEER changes — widening divergence signals falling ERPT
• Inflation expectations anchoring: surveys and breakeven inflation measures; de-anchoring amplifies ERPT
• Commodity currency episodes: AUD, CAD, NOK exhibit higher ERPT through commodity input channels
• Central bank communication on FX sensitivity thresholds in minutes and speeches