On Digital Currencies.

I discuss private and central-bank-issued digital currencies, summarizing my prior research. I argue that prices of private digital currencies such as bitcoin follow random walks or, more generally, risk-adjusted martingales. For central bank digital currencies, I argue that they enhance the trilemma facing a central bank. Of the three objectives, price stability, efficiency, and monetary trust, the central bak can achieve at most two. [ABSTRACT FROM AUTHOR]