High capital flow volatility and sudden stops are risky for emerging market economies. Capital controls, along with monetary policy, can help during crises. Optimal monetary policy should change during a crisis, diverging from price stability. Taxing capital inflows during a crisis is not the best approach for overall welfare. With policy commitment, capital inflows would be subsidized in crises. Using optimal monetary policy alone is better for welfare, but not consistent over time. Macro-prudential capital inflow taxes are not needed to prevent future crises.