May 22, 2004 Economists' long-standing interest in the degree to which exchange rate movements are reflected in prices was rekindled in the 1970s by a combination of rising inflation and the adoption of more flexible exchange rate regimes in many industrialized countries. Specifically, there were concerns that a large currency depreciation could degenerate into an inflationary spiral. Such fears were curtailed in the 1980s and early 1990s as industrialized countries began to reduce and stabilize their inflation rates. The low-inflation period most industrialized countries entered approximately a decade ago coincided with significant exchange rate depreciations that had much smaller effects on consumer prices than expected. This led to a belief that the extent to which exchange rate movements are passed through to consumer prices has declined. In this article, the authors examine why pass-through could be incomplete and review empirical estimates to determine whether pass-through has indeed declined, suggesting possible reasons for this decline and discussing the implications for monetary policy.