If all a CBDC did was to substitute for cash – if it bore no interest and came without any of the extra services we get with bank accounts1 – people would probably still want to keep most of their money in commercial banks. But even then it’s likely you’d see some money moving out of existing deposits. That drain would be greater the more closely a CBDC resembles a genuine bank account. One imagines it would also be counter-cyclical – resources would flow out of commercial banks during times of financial stress, back towards them when risk aversion is low. Shifting deposits to the central bank, and away from the leveraged commercial banking sector, has two important implications. On the one hand, it would probably make them safer. Currently, retail deposits are backed mainly by illiquid loans, assets that can’t be sold on open markets; if we all tried simultaneously to close our accounts, banks wouldn’t have the liquid resources to meet the demand. The central bank, by contrast, holds only liquid assets on its balance sheet. The central bank can’t run out of cash and therefore can’t suffer a “run”. On the other hand, taking deposits away from banks could impair their ability to make the loans in the first place. Banks would be more reliant on wholesale markets, a source of funding that didn’t prove particularly stable during the crisis, and could reduce their lending to the real economy as a result. This is the really main point I want to get across.
By contrast, the central bank essentially holds nothing but liquid assets – largely government securities (Chart 49). Shifting deposits away from commercial banks, and towards the central bank, would therefore make for a “narrower” banking system – a “narrow” bank being one whose assets are as liquid as its liabilities. In principle, it would also make for a safer one. Backed by liquid assets, rather than risky lending, deposits would become inherently more secure. They wouldn’t be vulnerable to “runs” and we would no longer need to insure them. 8  Nor is it a live issue for the Bank. As the Governor recently said to the House of Commons’ Treasury Committee, “May I…be absolutely clear: there are no plans to abolish cash at the Bank of England”. 9  The Bank of England’s balance sheet has obviously grown following QE. Those operations have been conducted via the Asset Purchase Facility (APF), which is not directly on the Bank’s balance sheet – strictly speaking, the blue bar in Chart 4 is not direct holdings of gilts but a loan from the Bank to the APF. But the APF itself holds only gilts and, even before QE, the vast majority of assets on the Bank’s balance sheet were government securities. BIS central bankers’ speeches  5  The case for narrow banks has a long and distinguished pedigree. The classical economists Adam Smith and David Ricardo favoured such a system.