Consider two small, open economies, Country A and Country B, that are both hit by the same sudden, large increase in domestic consumer confidence, leading to a surge in spending.

The institutional frameworks for their economic policy differ significantly:

• Country A: Has an independent central bank whose primary mandate is to maintain low and stable inflation. It operates under a flexible exchange rate regime, meaning the value of its currency is determined by market forces.
• Country B: The central bank's primary mandate is to maintain a fixed value for its currency against a major international currency.

Analyze how the immediate policy response of the central bank and the resulting short-term effect on domestic interest rates would likely differ between these two countries. Explain the reasoning behind these differences.