关键词: 存款乘数, 货币乘数, 货币创造, 双层存款乘数

Abstract: There are two main definitions of money multiplier in literature： one is “deposit multiplier”，and its brief connotation is the expansion multiple of deposit money under the legal reserve ratio requirement in the credit monetary system The other is “base money multiplier”，and its brief connotation is the expansion （or contraction） of broad money supply caused by the central bank's base money，that is，money multiplier = broad money quantity/base money There is a close internal relationship between these two multipliers However，whether it is deposit multiplier or money multiplier，their theoretical logic is not rigorous and inconsistent with practical logic
There are three main defects in the traditional theory of money multiplier： First，when the mainstream theory focuses on the deposit multiplier of the commercial banking system，it ignores the mechanism that the central bank，as a bank，also creates money by connecting deposits and loans，and thus ignores the multiplier mechanism and deposit multiplier at the level of central bankcommercial banks Second，the logical deduction of the base money multiplier in the mainstream theory is based on the deposit multiplier of a single commercial bank，but it is directly applied to the money multiplier of the whole banking system including the central bank Third，the mainstream theory only analyzes the direct impact of changes in the statutory reserve ratio on the deposit multiplier of commercial banks It is believed that the adjustment of the statutory reserve ratio will directly affect the amount of deposits created by commercial banks，and thus affect the change of money supply and the size of money multiplier It is ignored that the funds obtained by the central bank through the adjustment of the statutory reserve ratio are not stored idle，but are used by the central bank for relending，rediscount，foreign exchange purchase and other operations of commercial banks and open market operation As a result，a deposit multiplier mechanism at the central bankCommercial bank level has been formed，making the adjustment of the statutory reserve ratio have little impact on the total amount of funds in the commercial banking system
We analyze the relationship between the two-tier banking system and the money multiplier，demonstrate the practical logic under the framework of the two-tier deposit multiplier，confirm the existence and operation logic of the twotier deposit multiplier mechanism with the actual data of China and the United States，and point out the misunderstandings of the theory of statutory deposit reserve ratio First，the statutory reserve ratio mechanism extends the regulation effect of the central bank on a single commercial bank to the entire commercial banking system，which makes a mistake of generalizing the whole Second，the statutory reserve ratio mechanism focuses on using the central bank mechanism to regulate the credit money creation of commercial banks，and does not take into account the fund operation after the adjustment of the statutory reserve ratio by the central bank Third，the statutory deposit reserve ratio mechanism is anchored in the central bank's regulation of the deposit multiplier of commercial banks in the creation of credit money，ignoring the central bank's deposit multiplier in the creation of credit money
Under the framework of twotier money multiplier mechanism of central bankcommercial banks and commercial banksclients，we propose new methods to calculate the money multiplier The first calculation method is to define the “money” in the money multiplier Km as the currency in circulation M0，and use it as the denominator of the money multiplier formula，so the circulation formula of the money multiplier is Km=（M2/M0）-1，where M2 is monetary aggregate The second calculation method is the money multiplier Kc under the condition of excluding time deposits T，then Kc=［（M2-T）/M0］-1

Key words: deposit multiplier, money multiplier, money creation, two-tier money multiplier