Which came first – coin or the ledger? In either case, physical currency or a tally of debts and payments have been the two primary forms of money used throughout history. Today, physical cash is increasingly being replaced with cashless systems including cryptocurrencies. This week, we hear from blockchain researcher Jaya Klara Brekke on the political economy of blockchain and consensus protocols. And we go to Athens where contributors Niki Seth-Smith and Alyssa Moxley look at how some Greeks have been using cryptocurrencies since banking restrictions were imposed in 2015.