Monetary policy is formulated by central banks to control money supply and achieve macroeconomic stability. The document discusses the objectives, instruments, and limitations of monetary policy. It explains that central banks use quantitative methods like bank rates, reserve ratios, and open market operations as well as qualitative methods like regulating consumer credit to influence money supply during inflationary and recessionary periods. However, monetary policy is not always effective due to factors such as an underdeveloped financial system, money not being borrowed from banks, and interest rates sometimes having unintended impacts.