We are heading for a cashless world. At some point, we will say goodbye to all those pieces of paper and polymer and switch to an electronic alternative. The only problem with these statements is that people have been saying them since the late 1960s. Banknotes have a robust technology and will...

Digital platforms, such as Alibaba and Amazon, operate an online marketplace to facilitate transactions. This paper studies a platform's business model choice between accepting cash and issuing tokens, as well as the implications for welfare, resiliency, and interoperability. A cash platform...

I explain the meaning of an interoperable payment system and why interoperability is crucial for efficiency. I review some alternative approaches to interoperability, including central bank digital currencies (CBDCs), hybrid CBDCs, and two-ledger upgrades of bank-based payment systems

How well can a cryptocurrency serve as a means of payment? Cryptocurrencies need to overcome double spending by using costly mining and by delaying settlement. We formalize this insight through an incentive constraint that rules out double spending and pins down the welfare costs of a...