Optimal reserve composition in the presence of sudden stops

We analytically derive optimal central bank portfolios in a minimum variance framework with two assets and transaction demands caused by sudden stops in capital inflows. In this model, transaction demands become less important relative to traditional portfolio objectives as debt to reserve ratios decrease. We empirically estimate optimal dollar and euro shares for 23 emerging market countries and find that optimal reserve portfolios are dominated by anchor currencies and, at current debt-to-reserve ratios, introducing transaction demand has a relatively modest effect for most countries. We find that, in general, the dollar acts as a safe haven currency during sudden stops for country specific and global sudden stops, increasing the optimal share of dollar bonds in central bank portfolios. Correspondingly, our model predicts that dollar shares should decline as debt-to-reserve ratios fall, as observed in recent data. We also find that the denomination of foreign currency debt has little importance for optimal reserve portfolios.     

Dollarization and currency exchange

We use a dual currency money search model to study dollarization. Agents hold portfolios consisting of two currencies, one of which is risky. We use numerical methods to solve for the steady-state distributions of currency portfolios, transaction patterns, and value functions. As risk increases, agents increasingly use the safe currency as a medium of exchange—dollarization occurs. Furthermore, the safe currency trades for multiple units of the risky currency. This type of currency exchange, and the corresponding nominal exchange rate, are often observed in black market or unofficial currency exchange markets in developing countries. Due to decentralized trading, a distribution of exchange rates arises, whose mean and variance change in predictable ways when currency risk increases.     

Using simulated currency rainbow options to evaluate covariance matrix forecasts

In the literature one can find a number of different methods to evaluate covariance matrix forecasts, and in choosing among these one has to consider what the actual purpose of the forecasts is. In this paper we look at portfolios of currency rainbow options and how simulated trading of such options portfolios can be used as a preference free evaluation measure for the forecasted covariance matrix. The main advantage of using portfolios instead of single options, in addition to making it possible to study multivariate problems of arbitrary size, is the possibility it gives to rely on shorter data series. We apply the methodology to a system of four US dollar exchange rates and compare the relative performance of different forecasting models, among them the fairly new Orthogonal GARCH model.     

Downside and upside risk spillovers between exchange rates and stock prices

We examined downside and upside risk spillovers from exchange rates to stock prices and vice versa for a set of emerging economies. We characterized the dependence structure between currency and stock returns using copulas and computed downside and upside value-at-risk and conditional value-at-risk. We documented a positive relationship between stock prices and currency values in emerging economies with respect to the US dollar and the euro, with downside and upside spillover risk effects transmitted both ways. Finally, we also documented asymmetries in upside and downside risk spillovers and asymmetric differences in the size of risk spillovers when the domestic currency values against the US dollar and the euro. Our results, consistent with flight-to-quality phenomena, have implications for downside and upside risk management of international investor portfolios in emerging markets.     

Bounds and prices of currency cross-rate options

This paper derives the pricing bounds of a currency cross-rate option using the option prices of two related dollar rates via a copula theory and presents the analytical properties of the bounds under the Gaussian framework. Our option pricing bounds are useful, because (1) they are general in the sense that they do not rely on the distribution assumptions of the state variables or on the selection of the copula function; (2) they are portfolios of the dollar-rate options and hence are potential hedging instruments for cross-rate options; and (3) they can be applied to generate bounds on deltas. The empirical tests suggest that there are persistent and stable relationships between the market prices and the estimated bounds of the cross-rate options and that our option pricing bounds (obtained from the market prices of options on two dollar rates) and the historical correlation of two dollar rates are highly informative for explaining the prices of the cross-rate options. Moreover, the empirical results are consistent with the predictions of the analytical properties under the Gaussian framework and are robust in various aspects.     

The Share of Systematic Variation in Bilateral Exchange Rates

Sorting countries by their dollar currency betas produces a novel cross section of average currency excess returns. A slope factor (long in high beta currencies and short in low beta currencies) accounts for this cross section of currency risk premia. This slope factor is orthogonal to the high‐minus‐low carry trade factor built from portfolios of countries sorted by their interest rates. The two high‐minus‐low risk factors account for 18% to 80% of the monthly exchange rate movements. The two risk factors suggest that stochastic discount factors in complete markets' models should feature at least two global shocks to describe exchange rates.     

Trading activity,dealer concentration and foreign exchange market quality

We study the relation between foreign exchange market quality and both trading activity and dealer concentration by considering two currency pairs with significant differences along both dimensions – the Euro–US dollar and Canadian dollar–US dollar. A variance ratio test reveals over-reaction in currency prices, but that this is smallest when trading activity is high and dealer concentration at its peak. A GARCH model shows that over-reaction declines as trading activity and dealer concentration increase, with the results being stronger for the Euro. Our results confirm that trading activity is an important determinant of market quality, but also point to a significant role for dealer concentration.     

Too Big to Change: The Stabilizing Force of Reserve Currency Preferences in the International Monetary System

We empirically investigate whether reserve currency preferences have been a source of stability for the international monetary system. Our findings suggest that reserve-hoarding countries, especially the emerging/developing countries, tend to adopt a stabilizing diversification strategy in their reserve portfolio allocation, buying (selling) assets denominated in depreciated (appreciated) currency. The result is robust to both International Monetary Fund and Bank for International Settlements measures of quantity changes of reserve shares. The stabilizing diversification strategy reveals the fact that reserve-hoarding countries may fall into a "dollar trap," and escaping from it may cause more valuation loss of their existing reserve portfolios.     

Overstatement of Implied Variance in the Dollar/Yen Currency Option Market

This paper investigates the predictive power of implied variancesextracted from the dollar/yen option prices. Implied variances areestimated from transaction prices of currency options traded on PHLXusing the option pricing model of Garman and Kohlhagen (1983). Incontrast to recent findings on stock and stock index options, theout-of-sample tests indicate that the implied variance is an upwardbiased estimator of future variance; and that the variance forecastsfrom GARCH and historical models do not contain significantincremental information in predicting future variance. Tradingstrategies are also developed to exploit the observed overstatementof variance in the dollar/yen option market. Traders that can executethe delta-neutral trading strategies at the observed markettransaction prices could lock in a significant profits during theperiod examined. However, for investors that facing highertransaction costs, the magnitude of the profits is generally notlarge enough to allow for abnormal risk-adjusted profits.     

Pricing currency options in the presence of time-varying volatility and non-normalities

A new framework is developed for pricing currency options in the case where the distribution of exchange rate returns exhibits time-varying volatility and non-normalities. A forward-looking volatility structure is adopted whereby volatility is expressed as a function of currency returns over the life of the contract. Time to maturity and moneyness effects in volatility are also modelled. An analytical solution for the option price is obtained up to a one-dimensional integral in the real plane, enabling option prices to be computed efficiently and accurately. The proposed modelling framework is applied to European currency call options for the UK pound written on the US dollar, over the period October 1997–June 1998. The results show that pricing higher order moments improves both within-sample fit and out-of-sample prediction of observed option prices, as well as having important implications for constructing hedged portfolios and managing risk.     

The puzzling peso

In the past decade, some observers have noted an unusual aspect of the Mexican peso’s behavior: During periods when the U.S. dollar has risen (fallen) against other major currencies such as the euro, the peso has risen (fallen) against the dollar. Very few other currencies display this behavior. In this paper, we attempt to explain the unusual pattern of the peso’s correlation with the dollar by developing some general empirical models of exchange rate correlations. Based on a study of 29 currencies, we find that most of the cross-country variation in exchange rate correlations with the dollar and the euro can be explained by just a few variables. First, a country’s currency is more likely to rise against the dollar as the dollar rises against the euro, the closer it is to the United States and the farther it is from the euro area. In this result, distance likely proxies for the role of economic integration in affecting exchange rate correlations. Second, a country’s currency is more likely to exhibit this unusual pattern when its sovereign credit rating is more risky. This may reflect that currencies of riskier countries are less substitutable in investor portfolios than those of better-rated countries. All told, these factors well explain the peso’s unusual behavior, as Mexico both is very close to the United States and has a lower credit rating than most industrial economies.     

Did China Effectively Manage Its Foreign Exchange Reserves? Revisiting the Currency Composition Change

To estimate the currency composition of China’s foreign exchange reserves and assess its effectiveness of management, the constrained least square method and variance sensitive analysis are utilized, respectively. Based on portfolio accounting identities, the change of foreign exchange reserves was decomposed into the net purchase change and the non-purchase change. The newly constructed non-purchase change was used to estimate the latent currency composition. Empirical results show that by the end of 2015Q1, China held about 63.6% of its reserves in the U.S. dollar, 19.6% in the euro, 3.09% in the Japanese yen, 4.89% in the pound sterling, 2.22% in the Canadian dollar, 2.03% in the Australian dollar, and 0.09% in the Swiss franc. Although the currency composition kept relatively stable, more attention had been paid to the emerging international currencies. China decreased the U.S. dollar share during the subprime crisis, while resorted to the portfolio rebalance strategy since 2011. The euro share and the pound sterling share declined during the European sovereign debt crisis. The first derivative of the U.S. dollar was positive while those of other currencies were negative before 2014Q3, and vice versa after 2014Q4. In general, the currency composition management of China’s foreign exchange reserves was effective.     

Countercyclical currency risk premia

We describe a novel currency investment strategy, the ‘dollar carry trade,’ which delivers large excess returns, uncorrelated with the returns on well-known carry trade strategies. Using a no-arbitrage model of exchange rates we show that these excess returns compensate U.S. investors for taking on aggregate risk by shorting the dollar in bad times, when the U.S. price of risk is high. The countercyclical variation in risk premia leads to strong return predictability: the average forward discount and U.S. industrial production growth rates forecast up to 25% of the dollar return variation at the one-year horizon. The estimated model implies that the variation in the exposure of U.S. investors to worldwide risk is the key driver of predictability.     

Is there really a renminbi bloc in Asia?: A modified Frankel–Wei approach

This paper examines whether the renminbi (RMB) has supplanted the US dollar as the major anchor currency in the implicit currency baskets of East Asian economies. First, we demonstrate that existing techniques to address the problem of severe multicollinearity in estimations of the Frankel–Wei regression model, with the movements in both the US dollar and the RMB included on the right-hand side of the equation, remain limited in providing stable and robust results. We then propose a simple modification of the Frankel–Wei regression model to estimate the RMB weight in an economy's implicit currency basket. We show that this new method yields results that are superior to those obtained by existing techniques. Using the new method, we find that the US dollar continues to be the dominant anchor currency and that there is not yet an RMB bloc in East Asia, contrary to claims made by some recent studies. The RMB has taken on some importance in the implicit currency baskets of several East Asian economies in recent years and this appears to have occurred at the expense of the yen. In short, despite the rising importance of the RMB, it has not eclipsed the US dollar as the dominant anchor currency in East Asia. These conclusions are robust to alternative specifications of the modified Frankel–Wei regression model and the use of a structural break estimation technique.     

Country and currency diversification of bond investments: do they really make sense for Swiss investors?

The inclusion of hedged or unhedged foreign currency bonds within a strategic asset allocation is a crucial decision which should be analyzed carefully. The goal of this paper is to provide a contribution to this analysis by focusing particularly on the time horizon of the investment. Results are analyzed from the perspective of a Swiss investor. We find that over the last 21 years, investing in bonds denominated in Swiss Francs has been clearly less efficient in terms of risk-adjusted returns than investing in a hedged global bond portfolio. For short-term investors, we find robust evidence against the hypothesis of investing in unhedged foreign currency bonds. The picture changes dramatically, however, when we consider an investment horizon of 6 years and the normal case of balanced portfolios including also equities and domestic bonds. In this case, the optimal strategy for the period we analyzed would have been to hedge only the exposure to US dollar bonds.      

Oil Currency and the Dollar Standard: A Simple Analytical Model of an International Trade Currency

The U.S. dollar is the central reference currency for international trade pricing and the main invoicing currency for primary commodities. This paper links these two observations within a stylized theoretical framework, and shows how to obtain a quantitative estimate of the gain to the U.S. economy when the dollar is a reference currency. With dollar invoicing of primary commodities, U.S. firms bear less exchange rate risk than foreign firms. This asymmetry leads to a dollar standard in international goods pricing. We then derive a simple analytical formula to calculate the gains and find that they are extremely small.     

Asymmetric volatility in the foreign exchange markets

We examine the presence or absence of asymmetric volatility in the exchange rates of Australian dollar (AUD), Euro (EUR), British pound (GBP) and Japanese yen (JPY), all against US dollar. Our investigation is based on a variant of the heterogeneous autoregressive realized volatility model, using daily realized variance and return series from 1996 to 2004. We find that a depreciation against USD leads to significantly greater volatility than an appreciation for AUD and GBP, whereas the opposite is true for JPY. Relative to volatility on days following a positive one-standard-deviation return, volatility on days following a negative one-standard-deviation return is higher by 6.6% for AUD, 6.1% for GBP, and 21.2% for JPY. The realized volatility of EUR appears to be symmetric. These results are robust to the removal of jump component from realized volatility and the sub-samplings defined by structural-changes. The asymmetry in AUD, GBP and JPY appears to be embedded in the continuous component of realized volatility rather than the jump component.     

The forecasting ability of correlations implied in foreign exchange options

This paper evaluates the forecasting accuracy of correlations derived from implied volatilities in dollar-mark, dollar-yen, and mark-yen options from January 1989 to May 1995. As a forecast of realized correlation between the dollar-mark and dollar-yen, implied correlation is compared against three alternative forecasts based on time series data: historical correlation, RiskMetrics' exponentially-weighted moving average correlation, and correlation estimated using a bivariate GARCH(1,1) model. At the 1-month and 3-month forecast horizons, we find that implied correlation outperforms, often significantly, these alternative forecasts. In combinations, implied correlation always incrementally improves the performance of other forecasts, but not the converse; in certain cases, historically-based forecasts contribute no incremental information to implied forecasts. The superiority of the implied correlation forecast holds even when forecast errors are weighted by realized variances, reflecting correlation's contribution to the dollar variance of a multicurrency portfolio.     

Safehavenness of currencies

This study assesses the ‘safehavenness’ of a number of currencies with a view to providing a better understanding of how capital flow tends to react to a sharp increase in global risk aversion in turbulent times. It focuses on how the currencies are perceived by international investors or, more specifically, whether they are seen as safe-haven or risky currencies. To assess the safehavenness of the currency, we use risk reversal, which is the price difference between the call and put options of a currency, as it reflects how disproportionately market participants are willing to pay to hedge against its appreciation or depreciation. The relationship between the risk reversal of the currency and global risk aversion is estimated by means of parametric and non-parametric regressions that allow us to capture currency behaviour in times of extreme adversity, that is, the tail risk. Our empirical results found the Japanese yen and, to a lesser extent, the Hong Kong dollar to be the only safe havens under stressful conditions among the 34 currencies vis-à-vis the US dollar.