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
