Yann Koby

Bio: Yann Koby is an academic researcher from Princeton University. The author has contributed to research in topics: Monetary policy & Interest rate. The author has an hindex of 1, co-authored 1 publications receiving 137 citations.

The Reversal Interest Rate

Abstract: The reversal interest rate is the rate at which accommodative monetary policy reverses and becomes contractionary for lending. Its determinants are 1) banks' fixed-income holdings, 2) the strictness of capital constraints, 3) the degree of pass-through to deposit rates, and 4) the initial capitalization of banks. Quantitative easing increases the reversal interest rate and should only be employed after interest rate cuts are exhausted. Over time the reversal interest rate creeps up since asset revaluation fades out as fixed-income holdings mature while net interest income stays low. We calibrate a New Keynesian model that embeds our banking frictions.

Making Sense of Negative Nominal Interest Rates

Abstract: Several advanced economies implemented negative nominal interest rates in the middle of the last decade, seeking to provide further monetary accommodation once cuts in positive territory had been exhausted. Negative rates affect banks in novel ways, mostly because during times of negative policy rates the interest rate that banks pay households on their deposits usually remains close to zero. In this review, we analyze the large literature that studies the impact of negative nominal interest rates, proceeding in four steps. First, we explain the theoretical channels through which negative rates affect banks. Second, we discuss the empirical findings about bank outcomes under negative rates. Third, we describe the aggregate transmission channels that influence the macroeconomic implications of a policy rate cut in negative territory. Finally, we compare the general-equilibrium models that have been used to quantify the effectiveness of negative rates and highlight why they have obtained mixed results. We conclude that, if properly implemented, negative rates are a valuable tool that central banks should not discard outright. However, negative rates can have quantifiable costs for the financial sector, and their effectiveness is likely to decline if implemented for long periods.

The Reversal Interest Rate *(cid:132)

Abstract: The reversal interest rate is the rate at which accommodative monetary policy reverses and becomes contractionary for lending. We theoretically demonstrate its existence in a macroeconomic model featuring imperfectly competitive banks that face financial frictions. When interest rates are cut too low, further monetary stimulus cuts into banks’ profit margins, depressing their net worth and curtailing their credit supply. Similarly, when interest rates are low for too long, the persistent drag on bank profitability eventually outweighs banks’ initial capital gains, also stifling credit supply. We quantify the importance of this mechanism within a calibrated New Keynesian model.

The Deposits Channel of Monetary Policy

Abstract: We propose and test a new channel for the transmission of monetary policy. We show that when the Fed funds rate increases, banks widen the interest spreads they charge on deposits, and deposits flow out of the banking system. We present a model in which imperfect competition among banks gives rise to these relationships. An increase in the nominal interest rate increases banks' effective market power, inducing them to increase deposit spreads. Households respond by substituting away from deposits into less liquid but higher-yielding assets. Using branch-level data on all U.S. banks, we show that following an increase in the Fed funds rate, deposit spreads increase by more, and deposit supply falls by more, in areas with less deposit competition. We control for changes in banks' lending opportunities by comparing branches of the same bank. We control for changes in macroeconomic conditions by showing that deposit spreads widen immediately after a rate change, even if it is fully expected. Our results imply that monetary policy has a significant impact on how the financial system is funded, on the quantity of safe and liquid assets it produces, and on its lending to the real economy.

Life Below Zero: Bank Lending Under Negative Policy Rates

Abstract: This paper studies the transmission of negative monetary-policy rates via the lending behavior of banks. Unlike for positive rates, the transmission of negative rates depends on banks' funding structure. High-deposit banks take on more risk and lend less than low-deposit banks. Part of the risk taking comes in the form of new syndicated loans to risky firms without such loans previously, and it is limited to poorly-capitalized banks. Safe borrowers switch from high-deposit to low-deposit banks. The new risky borrowers appear financially constrained, and use the new funding to invest. For identification, we rely on a difference-in-differences approach. Banks with different reliance on deposit funding experience a different pass-through of negative policy rates. To isolate borrowers from interest-rate changes, we use lenders located in a different currency zone. A placebo at the time when policy rates fall -- but are still positive -- shows no effect. The results point to distributional consequences of negative policy rates with potential risks to financial stability.

Life below Zero: Bank Lending under Negative Policy Rates

Abstract: We show that negative policy rates affect the supply of bank credit in a novel way. Banks are reluctant to pass on negative rates to depositors, which increases the funding cost of high-deposit banks, and reduces their net worth, relative to low-deposit banks. As a consequence, the introduction of negative policy rates by the European Central Bank in mid-2014 leads to more risk-taking and less lending by euro-area banks with a greater reliance on deposit funding. Our results suggest that negative rates are less accommodative and could pose a risk to financial stability, if lending is done by high-deposit banks.Received April 17, 2018; editorial decision September 18, 2018 by Editor Philip Strahan. Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online.

A tale of two decades: The ECB's monetary policy at 20

Abstract: The 20th anniversary of Economic and Monetary Union (EMU) offers an opportunity to look back on the ECB’s record and learn lessons that can improve the conduct of policy in the future. This paper charts the way the ECB has defined, interpreted and applied its monetary policy framework – its strategy – over the years from its inception, in search of evidence and lessons that can inform those reflections. Our “Tale of Two Decades” is largely a tale of “two regimes”: one – stretching slightly beyond the ECB’s mid-point – marked by decent growth in real incomes and a distribution of shocks to inflation almost universally to the upside; and the second – starting well into the post-Lehman period – characterised by endemic instability and crisis, with the distribution of shocks eventually switching from inflationary to continuously disinflationary. We show how the most defining element of the ECB’s monetary policy framework, its characteristic definition of price stability with a hard 2% ceiling, functioned as a key shock-absorber in the relatively high-inflation years prior to the crisis, but offered a softer defence in the face of the disinflationary forces that hit the euro area in its aftermath. The imperative to halt persistent disinflation in the post-crisis era therefore called for a radical, unprecedented policy response, comprising negative policy rates, enhanced forms of forward guidance, a large asset purchase programme and targeted long-term loans to banks. We study the multidimensional interactions among these four instruments and quantify their impact on inflation and economic activity. JEL Classification: E50, E51, E52

The European Central Bank's Monetary Policy during Its First 20 Years

Abstract: ABSTRACT:On June 1, 2018, the European Central Bank (ECB) celebrated its 20th anniversary. This paper provides a comprehensive view of the ECB's monetary policy over these two decades. The first section gives a chronological account of the macroeconomic and monetary policy developments in the euro area since the adoption of the euro in 1999, going through four cyclical phases "conditioning" ECB monetary policy. We describe the monetary policy decisions from the ECB's perspective and against the background of its evolving monetary policy strategy and framework. We also highlight a number of the key, critical issues that were the subject of debate. The second section contains various assessments. We analyze the achievement of the price stability mandate and developments in the ECB's credibility, and we also investigate the ECB's interest rate decisions through the lens of a simple empirical interest rate reaction function. Finally, we present the ECB's framework for thinking about nonstandard monetary policy measures and review the evidence on their effectiveness. One of the main themes of the paper is how the ECB utilized its monetary policy to respond to the challenges posed by the European twin financial and sovereign debt crises and the subsequent slow economic recovery, making use of its relatively wide range of instruments, defining new ones where necessary, and developing the strategic underpinnings of its policy framework.