Please combine the money supply model (J?tunheimr model) to try to analyze the role of the central bank and commercial banks in the money supply.

J?tunheimr model is a general model to determine the money supply. According to this model, the money supply depends on the base currency, the statutory reserve ratio of demand deposits, the statutory reserve ratio of time deposits (this factor has now been abolished), the excess reserve ratio, the fixed deposit ratio and the currency ratio. Among them, the first three factors are determined by the central bank; The excess reserve ratio is determined by commercial banks, and the latter two factors are determined by the public.

Expressed by the formula, it is m1= (1+k) h/(rd+re+k).

What the central bank can decide is Rd, and commercial banks can decide Re, K and H by the public.

Then it is obvious that the central bank will tighten monetary policy, raise the deposit reserve ratio, and the money supply will decrease; Or commercial banks feel that the policy direction of the central bank has increased the excess reserve ratio, and the money supply will also decrease.

This is the principle. Add some woRds to ramble, analyze the definitions of rd, Re, k and h, and explain which ones are decided by the public and why.