摘要：

This paper derives the optimal monetary policy in a small open economy with endogenous productivity. The optimal policy is a targeting rule of inflation, the output gap, and the terms-of-trade, highlighting a trade-off between international purchasing power and the cost of importing R&D. Under a positive technology shock, an expansionary monetary policy that induces currency depreciation accelerates technological convergence by reducing R&D investment. To leverage this mechanism, central banks adopt a more aggressive interest rate adjustment. Using data from Taiwan, the optimal monetary policy exhibits three times greater variation than the standard Taylor rule and twice the variation of the optimal monetary policy under an exogenous productivity. The optimal monetary policy significantly improves welfare relative to the standard Taylor rule.