Joshua Gans, Neil Gandal, 06 February 2020

Cryptocurrencies such as Bitcoin rely on a ‘proof of work’ scheme to allow nodes in the network to ‘agree’ to append a block of transactions to the blockchain, but this scheme requires real resources (a cost) from the node. This column examines an alternative consensus mechanism in the form of proof-of-stake protocols. It finds that an economically sustainable network will involve the same cost, regardless of whether it is proof of work or proof of stake. It also suggests that permissioned networks will not be able to economise on costs relative to permissionless networks.

Raphael Auer, 08 March 2019

Bitcoin and related cryptocurrencies are exchanged via simple technical protocols for communication between participants, as well as a publicly shared ledger of transactions known as a blockchain. This column discusses research on how cryptocurrencies verify that payments are final, that is, that they are irreversible once written into the blockchain. It points to the high costs of achieving such finality via ‘proof-of-work’ and to a crucial externality in the transaction market, and argues that with the current technology, the liquidity of cryptocurrencies is set to shrink dramatically in the years to come.

CEPR Policy Research