Idle liquidity, CBDC and banking
构建模型研究付息央行数字货币是否会导致金融脱媒，发现CBDC与银行存款互补，提高CBDC利率可能促进投资并未必减少银行贷款，对理解CBDC对银行业和宏观经济的影响有参考价值。
We build models with an interest-bearing central bank digital currency (CBDC) to investigate whether the interest-bearing CBDC can lead to financial disintermediation. In the benchmark model with only CBDC, entrepreneurs can deposit their idle CBDC and banks can hold CBDC to satisfy the reserve requirement. CBDC and bank deposits become complements. A higher CBDC interest rate always promotes investment and may or may not reduce bank lending, because the higher return on CBDC encourages entrepreneurs to accumulate more CBDC and deposit more. More deposits could in turn lead to more bank lending. The interest rate on reserves and the reserve requirement ratio can be effective policy tools that affect bank lending and investment. We consider extensions where cash and interest-bearing CBDC can coexist. The coexistence may require the central bank to adjust the CBDC interest rate or the interest rate on reserves. Our results suggest that the relationship between CBDC and bank deposits are crucial for understanding the effects of CBDC on banking and the macroeconomy.