This paper investigates the granular transmission of U.S. monetary policy shocks to deviations from the uncovered interest rate parity (UIPDs) in emerging economies. Using a comprehensive dataset from Chile that accounts for firm-bank relationships and the time-variant characteristics of both firms and banks, we uncover several key findings: (1) Shocks to the federal funds rate (FFR) increase banks’ costs of foreign borrowing. (2) These higher credit costs disproportionately affect small firms, raising their UIPDs more than for large firms. (3) This size-differentiated impact stems from the relatively higher interest rates on domestic currency loans faced by small firms. (4) In contrast, interest rates on dollar-denominated loans respond homogeneously across all firms. (5) We find no differential effect on loan quantities, suggesting an active role of credit supply and demand. We rationalize these findings with a small open economy model of corporate default that incorporates heterogeneous firms borrowing from domestic banks in both foreign and domestic currencies. In our model, a higher FFR reduces the marginal cost of defaulting on domestic-currency debt for small firms more than for large firms.
