Abstract
This paper explores the 'evolutionary tree' of electronic cash using a series of case studies; presents a taxonomy to facilitate a discussion of the strategic options available for central bank digital currencies; and highlights the three practical alternatives
for implementing such a currency: as balances maintained offline in tamper-resistant hardware ('FedDex'); as balances maintained online in a database ('FedPesa'); or as tokens managed by an online shared ledger ('FedCoin'). The paper concludes with the observation
that a FedCoin solution may offer the most opportunities for innovation and economic growth. The idea of some form of FedCoin as a platform not just for smart money but very smart money is appealing in the central bank context as a way to implement the population-scale electronic cash system
required to deliver a national digital currency. This is important because the renewed focus of central banks on the potential for central bank digital currencies should highlight the potential for electronic cash as a platform for new opportunities and a new generation of financial services,
not simply a more efficient means to implement domestic retail payments. There is some urgency to this, as the beta testing of a Chinese digital currency is already underway.