In response to the Global Financial Crisis, central banks engaged in large-scale asset purchases funded by the issuance of reserves. These "unconventional" policies continued during the pandemic, so that by 2022 central banks' balance sheets had grown up to ten-fold. As a result of rapidly...

Before the era of large central bank balance sheets, banks relied on incoming payments to fund outgoing payments in order to conserve scarce liquidity. Even in the era of large central bank balance sheets, rather than funding payments with abundant reserve balances, we show that outgoing...

We conduct a systematic analysis of the costs and benefits of large-scale securities purchases, using the Federal Reserve's QE4 program as a concrete example. This program was initiated at the onset of the pandemic in March 2020 and continued for two years, leading to a doubling of the Fed's...

The fiscal theory states that inflation adjusts so that the real value of government debt equals the present value of real primary surpluses. Monetary policy remains important. The central bank can set an interest rate target, which determines the path of expected inflation, while news about the...

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...

The gold standard emerged as the international monetary system by the end of the 19th century. We formally study its properties in a micro-founded model and find that the scarcity of the world gold stock not only results in a suboptimal output of goods that are purchased with money but also...

Do periods of persistently loose monetary policy increase financial fragility and the likelihood of a financial crisis? This is a central question for policymakers, yet the literature does not provide systematic empirical evidence about this link at the aggregate level. In this paper we fill...

Financial technology has reshaped commercial banking. It has the potential to radically alter the transmission of monetary policy by lowering search costs and expanding bank markets. This paper studies the reaction of online banks to changes in federal fund rates. We find that these banks...

We examine the transmission of monetary policy shocks to the long-duration liabilities of households and firms using high-frequency variation in 10-year swap rates around FOMC announcements. We find that four weeks after the announcement mortgage rates move one-for-one with 10-year swap rates,...

We consider the debut of a new monetary instrument, central bank digital currencies (CBDCs). Drawing on examples from monetary history, we argue that a successful monetary transformation must combine microeconomic efficiency with macroeconomic credibility. A paradoxical feature of these...