Journal Publications
Foreign Exchange Intervention: A Dataset of Public Data and Proxies (with G. Adler, K. S. Chang and Y. Shao), 2025, Journal of Money, Credit and Banking, Volume 57 (5), pp. 1241-1273 [Published Paper] [IMF working paper] [Data]
Abstract: A better understanding of foreign exchange intervention (FXI) is often hindered by the lack of data. This paper provides a new dataset of FXI covering a large number of countries over the period 2000-22 at monthly and quarterly frequencies. It includes published official data for about 40 countries as well as carefully constructed estimates for 122 countries. Estimates account for a wide range of central bank operations, including both spot and derivative transactions. These estimates improve upon traditional proxies based on changes in reserves, by adjusting for valuation changes, income flows, and changes in other foreign-currency balance sheet positions (both vis-à-vis residents and non-residents)—the first estimates to do the latter to our knowledge—thus providing a more accurate measure of operations that change the central bank’s foreign currency position. The dataset also provides a classification of FXI operations into sterilized or not sterilized, a key dimension for economic analysis. Finally, the paper discusses the merits of the new estimates relative to traditional proxies, and presents stylized facts.
Do FX Interventions Lead to Higher FX Debt? Evidence from Firm-Level Data (with Minsuk Kim and Mico Mrkaic), 2024, Journal of International Money and Finance, Volume 148, 103160 [Published Paper] [IMF working paper]
Abstract: Central banks often buy or sell reserves—so called FX interventions (FXIs)—to dampen sharp exchange rate movements caused by volatile capital flows. At the same time, these interventions may entail unintended side effects. In this paper, we investigate whether FXIs incentivize firms to take on more unhedged FX debt, thereby increasing medium-term corporate vulnerabilities. Using a novel dataset with close to 5,000 nonfinancial firms across 19 emerging markets covering 2002–2017, we find that the firm-level share of FX debt rises following intensive use of FXIs, particularly for non-exporting firms in shallow financial markets with no FX debt to begin with. The magnitude of this effect is economically significant, with one standard deviation increase in the intensity of FXI leading to an average 2 percentage points increase in the FX debt share. For reference, the median share of FX debt in the sample is zero.
The Wage Phillips Curve under Labor Market Power (with A. Burya, Y. Timmer and A. Weber), 2023, AEA Papers and Proceedings, Volume 113, pp. 110-13 [Published Paper]
Abstract: To shed light on potential linkages between labor market power and the trade-off between unemployment and wages, this paper uses a highly disaggregated dataset of 250 million online vacancy postings in the United States from Lightcast (formerly Burning Glass Technologies). Labor market power is measured by the Herfindahl-Hirschman index (HHI) of vacancies in a commuting zone and is found to be more prevalent in less densely populated rural areas, where average incomes tend to be lower and job seekers have fewer employers to choose from. We estimate the Phillips curve at the commuting zone level and exploit regional variation in the degree of labor market power. The relationship between unemployment and wage inflation is found to be very weak across regions with high labor market power. These empirical findings are consistent with a dynamic monopsony search-and-matching model where firms can increase hiring by either offering higher wages or posting more vacancies (Manning 2006). Hence, in regions where firms have a large degree of labor market power, they face less competition and can hire workers without having to raise wages as much, which weakens the relationship between employment and changes in wages and therefore leads to a flatter wage Phillips curve. Using these insights, we conclude by laying out potential implications, particularly on income polarization, of the ongoing monetary policy tightening of the Federal Reserve in light of the existing pattern of labor market power across US regions.
Mask Mandates Save Lives (with N-J. Hansen), 2023, Journal of Health Economics, Volume 88, 102721, [Published Paper] [IMF working paper] [VoxEU]
Abstract: We quantify the effect of mask mandates in the United States. Our regression discontinuity design exploits county-level variation in COVID-19 cases, hospital admissions, and deaths across the border between states with and without mandates. We find a significant and substantial effect—mask mandates reduced new weekly COVID-19 cases, hospital admissions, and deaths by 55, 11 and 0.7 per 100,000 inhabitants on average. Crucially, we find that the effect of mask mandates depends on the attitudes toward mask wearing at the county level, with larger effects in counties more positively inclined towards mask wearing. Our results imply that mandates saved 87,000 lives through December 19, 2020, while a nationwide mandate could have saved 58,000 additional lives. These large effects suggest that mask mandates are a crucial tool to counter pandemics, particularly if accepted widely by the population. Our results are thus also relevant for countries who will not be able to immunize large swaths of their population in the short term.
COVID-19 Vaccines: A Shot in Arm for the Economy (with N-J. Hansen), 2023, IMF Economic Review, Volume 71, pp. 148-169 [Published Paper] [IMF working paper] [VoxEU]
Abstract: We quantify the effect of vaccinations on economic activity in the United States using weekly county level data covering the period end-2020 to mid-2021. Causal effects are identified through instrumenting vaccination rates with county-level pharmacy density interacted with state-level vaccine allocations, and by including county and state-time fixed effects to control for unobserved factors. We find that vaccinations are a significant and substantial shot in the arm of the economy. Specifically, spending rises by 1.3 percentage points (relative to the average spending during January 2020) in response to a 1 percentage point increase in initiated vaccination rates. Initial unemployment decreases by 0.009 percentage points of the 2019 labor force over the same time horizon. Vaccinations also increase workplace mobility. Urban counties and counties with initially worse socioeconomic conditions and lower education levels exhibit larger effects of vaccinations.
The Cost of FX intervention: Concepts and Measurement (with Gustavo Adler), 2021, Journal of Macroeconomics, Volume 67, 103045. [Published Paper] [SSRN] [IMF working paper]
Abstract: The accumulation of large foreign asset positions by many central banks through sustained foreign exchange (FX) intervention has raised questions about its associated fiscal costs. This paper clarifies conceptual issues regarding how to measure these costs both from an ex-post and an ex-ante (relevant for decision making) perspective, and estimates both marginal and total costs for 73 countries over the period 2002-13. We find ex-ante marginal costs for the median emerging market economy (EME) in the inter-quartile range of 2-5.5 percent per year; while ex-ante total costs (of sustaining FX positions) in the range of 0.2-0.7 percent of GDP per year for light interveners and 0.3-1.2 percent of GDP per year for heavy interveners. These estimates indicate that fiscal costs of sustained FX intervention (via expanding central bank balance sheets) are not negligible.
Real Exchange Rate and External Balance: How Important Are Price Deflators? (with JaeBin Ahn and Jing Zhou), 2020, Journal of Money, Credit and Banking, Volume 52, Issue 8, pp. 2111-2130. [Published Paper] [SSRN] [IMF working paper]
Abstract: This paper contrasts real exchange rate (RER) measures based on different deflators (CPI, GDP deflator, and ULC) and discusses potential implications for the link—or lack thereof—between RER and external balance. We begin by documenting patterns in the evolution of different measures of RERs, and confirm that the choice of deflator plays a significant role in RER movements. A subsequent empirical investigation based on 35 developed and emerging market economies over 1995 to 2014 yields comprehensive and robust evidence that only the RER deflated by ULC exhibits contemporaneous patterns consistent with the expenditure-switching mechanism. We rationalize the empirical findings by introducing a simple model featuring nominal rigidity and trade in intermediate goods as the one in Obstfeld (2001) and Devereux and Engel (2007), which is shown to generate qualitatively identical patterns to empirical findings.
Unveiling the Effect of Foreign Exchange Intervention: A Panel Approach (with Gustavo Adler and Noemie Lisack), 2019, Emerging Markets Review, Volume 40, 100620. [Published Paper] [SSRN] [IMF working paper]
Abstract: The paper studies the effect of foreign exchange intervention on the level of the exchange rate relying on an instrumental-variable panel approach suited to assess the macroeconomic importance of such effect (i.e., beyond short-term effects found in the literature). We find robust evidence that intervention affects the exchange rate in a meaningful way from a macroeconomic perspective. A purchase of foreign currency of 1 percentage point of GDP causes a depreciation of the nominal and real exchange rates in the ranges of [1.7–2.0] percent and [1.4–1.7] percent, respectively. The effects are found to be persistent and symmetric for FX purchases and sales.
Forward and Spot Exchange Rates in a Multi-Currency World (with Tarek Hassan), 2019,The Quarterly Journal of Economics, Volume 134, Issue 1, Pages 397–450. [Published Paper] [VOX]
Abstract: Separate literatures study violations of uncovered interest parity (UIP) using regression-based and portfolio-based methods. We propose a decomposition of these violations into a cross-currency, a between-time-and-currency, and a cross-time component that allows us to analytically relate regression-based and portfolio-based facts, and to estimate the joint restrictions they place on models of currency returns. Subject to standard assumptions on investors’ information sets, we find that the forward premium puzzle (FPP) and the “dollar trade” anomaly are intimately linked: both are driven almost exclusively by the cross-time component. By contrast, the “carry trade” anomaly is driven largely by cross-sectional violations of UIP. The simplest model that the data do not reject features a cross-sectional asymmetry that makes some currencies pay permanently higher expected returns than others, and larger time series variation in expected returns on the US dollar than on other currencies. Importantly, conventional estimates of the FPP are not directly informative about expected returns, because they do not correct for uncertainty about future mean interest rates. Once we correct for this uncertainty, we never reject the null that investors expect high-interest-rate currencies to depreciate, not appreciate.
Default Premium (with Luís Catão), 2017, Journal of International Economics, Volume 107, Pages 91–110, [Published Paper] [Data & Online Appendix] [SSRN] [IMF working paper] [VOX]
Abstract: The literature has found that sovereigns with a history of default are charged only a small and/or short-lived premium on the interest rate warranted by observable fundamentals. We re-assess this view using a metric of such a “default premium” (DP) that nests previous metrics and applying it to a much broader dataset. We find a sizeable and persistent DP: in 1870-1938, it averaged 250bps upon market re-entry, tapering to around 150bps five years out; in 1970-2014 the respective estimates are about 350 and 200bps. We also find that: (i) the DP accounts for between 30 to 60 percent of the sovereign spread within five years of market re-entry, and its contribution to the spread remains non-negligible thereafter; (ii) The DP is higher for countries that take longer to settle with creditors and is on average higher for serial defaulters; (iii) our estimates are robust to many controls including realized “haircuts”. These findings help reconnect theory and evidence on why sovereigns default only infrequently and, when they do, why earlier debt settlements are typically sought.