[mike_hearn]

This is actually what CDBC proposals are about, at least originally. The idea is that by making the computing infrastructure of the central bank scale up and out, companies and even individuals can directly hold and transfer "hard money" i.e. money directly issued by the central bank, without needing an intermediary bank.

When I was last tangentially involved in such projects it was quite unclear how they thought this would interact with monetary policy. Narrow banks could easily be created today without any new IT systems, but generally, governments are unwilling to do what it takes to enable them for political and financial reasons. At some level it's another obfuscated way of raising revenue without explicitly raising taxes: they force people to deposit money in banks, force banks to lend those deposits to "low risk" counterparties like themselves giving them more money to spend on vote-winning policies, then if the banks go under they either print the money to bail them out (taxation via inflation), or force banks to charge the depositors (taxation with the banks as collectors), thus hiding the true nature of what's happening.

To get banks with zero risk deposits is therefore not really an infrastructure problem - banks could easily just park cash with the CB and then charge fees for administration of things like the websites, the branches and so on. The problem is to convince governments to reduce their spending levels to the point where they can eliminate the rules forcing banks to loan them money, which in turn would allow narrow banks/accounts to appear, and that in turn would allow them to start removing the guarantee on deposits. In such a system people who wanted ROI would have to explicitly move some deposits into funds that expose the liquidity risks and requirements, and which can be left to collapse without a bailout if they make big losses.

Unfortunately governments are currently stuck in a local minima. Although everyone can see that bank runs are bad, and that they're also easy to eliminate, doing so would require people to believe that the government will not bail out depositors at a fractional reserve bank if there's a run. For as long as people suspect the government's commitment to the policy is weak, the winning move is to keep banking with a fractional reserve bank and pocket the zero-risk interest yields. The suckers who put their money in a safer place will end up poorer than those who put their money into a bank that later collapses.