"Cryptocurrency is accounting coordination: Selfish mining and double spending in a simple mining game", with Jefferson Bertolai and Fernando Barros Jr - Mathematical Social Sciences, 2023.
Abstract: The fundamental monetary innovation embedded into cryptocurrencies is accounting coordination. Decentralized management of digital money’s accounting by a network of computers is achieved as a Nash equilibrium of a coordination game among the network’s nodes: the so called miners. Equilibrium analysis demands allowing miners to secretly update their accounting (privately build multiple blocks of transactions and deviate from the longest chain rule). We formalize such reasoning by proposing an accounting coordination game inspired on the Bitcoin design. By proposing a model that tells apart mining costs related to energy consumption from those related to computational capacity, symmetric equilibrium existence is shown to depend on well known parameters, like the average time for updating accounting records and the rewards collected from mining (accounting) activities. Also, the possibility of double spending makes the attractiveness of the equilibrium strategy a decreasing function of the average time for updating accounting records.
"Digital currencies and the brazilian real: a brief analysis" [in portuguese], 2021
Abstract: In May 24, 2021, the Central Bank of Brazil (BCB) presented to the public the guidelines for the potential development of the real in digital format. The news comes at a time when central banks have intensified efforts in the search for better responses to the challenges posed by the emergence of technological innovations that affect the way the financial structure is organized. This essay aims to organize some ideas about the evolution of the means of payments and the phenomenon of digital currencies, in order to enable a better understanding of the recent movement of governments and organizations towards a possible implementation of the so-called Central Bank Digital Currencies (CBDCs). Specially, I discuss the Brazilian case of developing its own electronic currency, analyzing the possible technologies and designs that can be adopted by the BCB in the configuration of the Digital Real.