An empirical study of nonlinear adjustment in the UIP model using a smooth transition regression model

This study considers the nonlinear relationship between the expected exchange rate change and the interest rate differential, using STR models (ESTR and LSTR), with Sharpe ratios, interest rate differentials and exchange rate volatilities as the transition variables. The results generally conclude that UIP holds with the larger Sharpe ratio and higher exchange rate volatility regimes, which is consistent with the transaction costs and limits to speculation hypotheses. However, the interest rate differential (which is generally not used much as a transition variable) when used in this study results in a failure to support UIP in the upper regime, which suggests it is the risk not the pure return that determines the transition.     

Differential risk premiums and the UIP puzzle

We respecify the uncovered interest rate parity (UIP) conditions by inverting the market price of the risk (Sharpe ratio) formula. Our empirical model provides new insight indicating that violations to the UIP stem from the existence of a risk premium in the exchange rates and from observed market return differentials being a noisy statistic of the markets’ expected return differentials in our respecified model. Using an integrated macro‐micro structure framework for expected market return differentials improves our model fit and the validity of UIP.     

Uncovered interest parity: The long and the short of it

Uncovered interest rate parity (UIP) is a theoretical relation linking changes in exchange rates and corresponding interest rate differentials. Despite its considerable intellectual appeal, uncovered interest rate parity has very often been found wanting empirically. I reinvestigate this relation using a 17-country panel of historical time series data at its longest—for the US–UK country pair—spanning 217 years. I find results that are largely consistent with theory: over the long term, in most countries, bond yields expressed in common currency bear a positive relationship to one another as UIP predicts. This is in contrast to the very nearly opposite findings reported in much of the literature and now taken as a stylized fact.     

Co-integrating currencies and yield differentials

This study investigates the relationship between currencies and interest rates of different maturity horizons. The real exchange rate is found to depend both on short-term real domestic and foreign interest rate difference and on long-term real domestic and foreign interest rate difference. Co-integrating regressions of contemporaneous currency rates generate negative and significant coefficients for long-term rate differentials, consistent with uncovered interest parity. Therefore, the expectations hypothesis holds for long horizons. On the other hand, positive coefficients for real short-term interest rate differentials reveal the forward premium puzzle: the failure of uncovered interest parity for short-horizons. Results are partly driven by the very different risk characteristics of short-term bonds and foreign bonds.     

Was It Real? The Exchange Rate-Interest Differential Relation over the Modern Floating-Rate Period

In this paper, we explore the relationship between real exchange rates and real interest rate differentials in the United States, Germany, Japan, and the United Kingdom. Contrary to theories based on the joint hypothesis that domestic prices are sticky and monetary disturbances are predominant, we find little evidence of a stable relationship between real interest rates and real exchange rates. We consider both in-sample and out-of-sample tests. One hypothesis that is consistent with our findings is that real disturbances (such as productivity shocks) may be a major source of exchange rate volatility.     

Time-varying international diversification and the forward premium

This paper reproduces the slope of the uncovered interest rate parity (UIP) regression for ten country pairs within one standard deviation under rational expectations. We propose an infinite horizon dynamic stochastic general equilibrium model with incomplete markets. Heterogeneous investors experience varying risk aversion as a result of habit formation.The underlying mechanism of the model relies on varying international diversification in the investors' portfolio choice decision. In response to their changing habit levels, investors' hedging desire varies over time. This leads to adjustments in interest rates. The habit-induced investment decisions are negatively correlated with movements in the exchange rate. This results in a negative correlation between interest rates and expected exchange rates, as implied by a negative UIP slope.Depending on the magnitude of habits, the model is capable of reproducing positive as well as negative UIP slopes, as seen empirically in the data.     

Interest Rates and Exchange Rate Movements: Analyzing Short-term Investments in Long-term Bonds

Tests of the uncovered interest rate parity (UIP) are subject to various data problems when long-term interest rates are applied: due to the long investment period, time intervals for measuring exchange rate movements are usually overlapping and therefore not independent. This shortfall can be prevented by considering short-term investments in long-term bonds instead of investments to maturity. This article analyzes the explanatory power of long-term interest rates with regard to 1- and 3-month exchange rate movements by relating return differences from 1- and 3-month investments in domestic and foreign 10-year government bonds to nine different exchange rates. From a Swiss perspective, there is only weak support for an interrelation between return differences and the corresponding exchange rate movements, whereas from a US perspective, the resulting estimates are much more in line with UIP.The reader may for instance consider Engel (1996) and Froot and Thaler (1990).     

Home bias,exchange rate disconnect,and optimal exchange rate policy

This paper examines how much the central bank should adjust the interest rate in response to real exchange rate fluctuations. The paper first demonstrates, in a two-country Dynamic Stochastic General Equilibrium (DSGE) model, that home bias in consumption is important to replicate the exchange rate volatility and exchange rate disconnect documented in the data. When home bias is high, the shock to Uncovered Interest rate Parity (UIP) can substantially drive up exchange rate volatility while leaving the volatility of real macroeconomic variables, such as GDP, almost untouched. The model predicts that the volatility of the real exchange rate relative to that of GDP increases with the extent of home bias. This relation is supported by the data. A second-order accurate solution method is employed to find the optimal operational monetary policy rule. Our model suggests that the monetary authority should not seek to vigorously stabilize exchange rate fluctuations. In particular, when the central bank does not take a strong stance against the inflation rate, exchange rate stabilization may induce substantial welfare loss. The model does not detect welfare gain from international monetary cooperation, which extends Obstfeld and Rogoff's [Obstfeld, M., Rogoff, K.,2002. Global implications of self-oriented national monetary rules, Quarterly Journal of Economics May, 503–535] findings to a DSGE model.     

RIP and the shift toward a monetary union: Looking for a “euro effect” by a structural break analysis with panel data

This paper aims to evaluate how the ex ante real interest rates of Euro area countries have been modified by the introduction of the euro. We use cointegration analysis with endogenous breaks in a panel data context. Our results show that the “euro effect” is significant in our sample and that after the introduction of the euro, the real interest parity (RIP) holds. This last conclusion is due to a decrease in the nominal interest rate differentials rather than to a reduction in goods and services price differentials and in the exchange rate volatility.     

Do fundamentals matter for the D-Mark/Euro–Dollar? A regime switching approach

In this paper, we demonstrate that there is evidence of an unstable and nonlinear relationship between fundamentals and exchange rates. Modeling this time-varying nature of the importance of fundamentals in a Markov switching framework substantially improves the fit of the real interest rate differential model and leads to parameter estimates, which in one regime are in line with theoretical expectations and allow us to draw reasonable conclusions on the influence of fundamentals on exchange rate dynamics. Factors that prove to be closely related to regime switches are short-term interest rate, inflation differentials and differences in economic growth. Therefore, fundamentals do not only matter for the exchange rate within each regime, but are also related to the switches between the regimes.     

Real interest parity: Evidence from trade partnerships

This study investigates real interest parity (RIP) in trade partnerships, and whether RIP depends on the type of trade partnership, using short term interest rates and the Consumer Price Index (CPI) obtained from the Organization for Economic Cooperation and Development (OECD) database between 1975 and 2016. The investigation employs unit root and stationarity tests on interest rate differentials to study RIP between countries using Germany, United States, and Japan as base countries for selected countries in the European Union (EU), member countries of the North American Free Trade Agreement (NAFTA) and selected Asian countries respectively. The results show evidence in favor of RIP in the selected EU countries. The interest rate differentials of Belgium, France, Italy, Spain and the UK with respect to Germany confirms a long‐run relationship and real interest rate parity. There is also evidence to support the RIP in the other trade partnerships. With the exception of Mexico, the interest rate differentials for all the countries are stationary, and each quickly reverts to its mean.     

A Habit-Based Explanation of the Exchange Rate Risk Premium

This paper presents a model that reproduces the uncovered interest rate parity puzzle. Investors have preferences with external habits. Countercyclical risk premia and procyclical real interest rates arise endogenously. During bad times at home, when domestic consumption is close to the habit level, the representative investor is very risk averse. When the domestic investor is more risk averse than her foreign counterpart, the exchange rate is closely tied to domestic consumption growth shocks. The domestic investor therefore expects a positive currency excess return. Because interest rates are low in bad times, expected currency excess returns increase with interest rate differentials.     

Long-term foreign exchange risk premia and inflation risk

As highlighted by recent literature, long-term foreign exchange risk premia (FRP) of a currency pair tend to covary negatively with short-term real interest rate differentials (RIRD) of the pair. We fit an affine term structure model for 9 major currencies against the US dollar and estimate two components of this covariance: the real risk premia (RRP) component and the inflation risk premia differential (IRPD) component. We find that the IRPD component is significantly negative for all currency pairs in our sample. We propose a macro-finance model to understand the types of shocks that generate such covariance.     

Stochastic intramarginal interventions in target zones

In this paper, we develop an exchange rate target zone model with stochastic intramarginal interventions that generalizes Krugman's standard model. We assume that money supply changes are (negative) proportional to the velocity shocks. The model produces realistic patterns for the relationship among exchange rate, fundamentals and interest rate differentials, which can explain some empirical failures of previous target zone models. The main result derived from the model is that non-linearities in the behavior of both exchange rate and interest rate differential disappear as intramarginal interventions increase.     

An exploration of the forward premium puzzle in currency markets

A standard empirical finding is that expected changes in exchangerates and interest rate differentials across countries are negativelyrelated, implying that uncovered interest rate parity is violatedin the data. This article provides new empirical evidence thatsuggests that violations of uncovered interest rate parity,and its economic implications, depend on the sign of the interestrate differential. A framework related to term structure modelsis developed to account for the puzzling relationship betweenexpected changes in exchange rates and interest rate differentials.Estimation results suggest that a particular term structuremodel can account for the puzzling empirical evidence.     

利差、美元指数与跨境资本流动

一般认为跨境资本流动由利差决定,政策制定也强调利差对资本流动的指示意义。但本文发现,中国跨境资本流动历史上主要是由套汇而非套息资本决定,且套汇的显著指标是多边美元指数(DXY)而非人民币兑美元双边汇率,我们把这一现象称之为“中国的跨境资本流动之谜”。我们提出,汇率影响大于利率且多边汇率影响大于双边汇率的原因在于人民币兑美元双边汇率历史上波动幅度较小,及时和充分反映中美基本面的分化还不够。美元指数是市场指标,能够预示人民币兑美元双边汇率的走势,进而驱动资本流动。进一步研究发现,由于中国经济的外溢效应,中美经济基本面的分化不仅决定中美利差,还在很大程度上驱动美欧、美日经济基本面的分化,进而略有时滞地驱动美元指数。因此,中美利差在统计意义上是美元指数的同步甚至略微领先的指标,从这个意义上讲,政策制定仍要关注利差。随着人民币汇率弹性增强,中美利差和美元指数对中国跨境资本流动的解释力都会边际减弱。     

The profitability of carry trades

The uncovered interest parity (UIP) condition suggests that carry trades whereby investors borrow in the low interest rate currency and invest in the high interest rate currency should not result in excess profits over the long run. In this paper, we test the significance of the conventional empirical failure of UIP condition. Using the four bilateral pound parities we fail to detect significant excess carry trade profits for the yen, euro and swiss franc–pound parities. The only parity for which the carry trade consistently makes excess profits is the dollar–pound parity. This result is somewhat surprising as this is the currency pair with the lowest interest rate differential. We are extremely grateful for the anonymous referee’s comments on this paper.     

Predicting exchange rate cycles utilizing risk factors

This paper attempts to predict the cyclical behavior of exchange rates by using five risk factors, viz., violations of uncovered interest rate parity (UIP), relative purchasing power parity (RPPP) and pseudo-parity for equity returns, relative (cross-country) TED spreads and relative term spreads. These factors are found to forecast periods of depreciation or appreciation and subsequent reversals. The estimates based on a dynamic probit model reveal that violations of UIP, RPPP and equity market pseudo-parity exhibit predictive power for currency cycles albeit only at short horizons. The proposed framework can be utilized by policy makers to smoothen the resulting currency misalignment and by investors to form trading strategies and hedge their positions as well as re-balance their carry trade positions.     

Real Exchange Rates and Fundamentals: A Cross‐Country Perspective

This paper employs newly constructed measures for productivity differentials, external imbalances, and commodity terms of trade to estimate a panel cointegrating relationship between real exchange rates and a set of fundamentals for a sample of 48 industrial countries and emerging markets. It finds evidence of a strong positive relation between the consumer price index‐based real exchange rate and commodity terms of trade. The estimated impact of productivity growth differentials between traded and nontraded goods, while statistically significant, is small. Increases in net foreign assets, government consumption, and trade restrictions tend to be associated with appreciating real exchange rates.     

Fractional cointegration and real exchange rates

This paper uses fractional integration and cointegration to model the DM-US dollar and the yen-US dollar real exchange rates in terms of both monetary and real factors, more specifically real interest rate and labour productivity differentials. We find that whilst the individual series may be integrated of order 1, their long-run relationship might have a fractionally cointegrated structure. This means that mean reversion occurs, consistently with the findings of other studies. However, it also indicates, in contrast to such studies, that the cointegrating relationship possesses long memory. In other words, the error correction term responds slowly to shocks, implying that deviations from equilibrium are long-lived. It appears that only a combination of real and monetary variables can accurately track down the movements of real exchange rates.