The policy maker mentioned in the article claims that credit is now more liquid than cash. This could be taken quite a number of ways. One way is to think tha

The policy maker mentioned in the article claims that credit is now more liquid than cash. This could be taken quite a number of ways. One way is to think that the conveniences of credit has made cash less relatively liquid (there are fewer goods, such as those online, that can be traded for credit whereas most things in the physical world can be traded for credit). Another way is to see this as a hedge against a currency backed by a US facing fundamental challenges to its place as the global leader (not just in finance), whose growth even with stimulation boasts a mere 0.2%; 7% under major competitors. Another way to see this (e.g. in these comments) is a strategic means for banks to try to institute consumer credit as a currency of their own. One could also think of it as a fed inspired policy trying to get cash into circulation. The point of inflation is so that those holding large amounts of currency can't sit on the currency and make money from doing nothing. Banks and finance basically allow people to do this despite inflation (tending to benefit the rich more than the poor in this case). Putting a negative growth rate on storage of cash simulates the same thing.