I would add one other thought on the demand for banknotes, which is more to do with human psychology. I suspect most people, however much they use cards, feel a degree of comfort from knowing that they also have cash in their wallet or purse, even if it is as a back-up. What does this analysis tell us about future demand for cash? As a central bank responsible for the issuance of banknotes, two principles are at the front of our thinking: first, that we issue central bank money, in the form of claims on the Bank of England; and second, that in doing so we must meet the public’s demand for our notes. By issuing central-bank money, we are providing both a means of payment and a store of value. But I think we should recognise that the paradox of banknotes that I have described indicates that there may well be a limit to the growth of the value of notes in circulation insofar as the use of banknotes as a means of payment is not increasing. This is, though, a broad assessment, and I would not wish to offer a judgment on the level at which the demand of the public to hold more banknotes will peak. An important reason for this uncertainty is that, as recent experience indicates, the demand for banknotes as a store of value is dependent on the state of the economy and the financial system.
We can all observe around us the growth of the ATM industry, but it is worth considering how influential it has been on the circulation of banknotes. First, the rise of the ATM has fundamentally changed and modernised the distribution of what is sometimes regarded as an old-fashioned means of payment. Second, it is likely that the growth of ATMs may have led to an increase in notes in circulation for another reason. BIS Review 162/2009  5  When we talk to ATM operators about their business model they stress that the least acceptable outcome is for their ATMs to run out of notes. As a consequence, ATMs are restocked well before they run out. This means that the overall ATM estate is holding what could be described as idle inventory stock, but these are defined as notes in circulation. But I should be clear that I don’t have enough evidence to prove to you that the stock:output ratio for banknotes has gone up, which would run counter to the story in almost all other industries. I want to move on now to trends in cash usage (I am using “cash” here to mean banknotes and coin). Chart 8 shows survey evidence for the use of cash in retail transactions in the UK over the last 25 years. In terms of the share of the total volume of transactions, cash has fallen from over 80% in the mid 1980s to 60% currently.