Price level convergence and regional Phillips curves in the US and EMU

We use panel estimates of regional Phillips curves of the hybrid New Keynesian type to study price level convergence within the US and EMU. Regional inflation rates tend to eliminate PPP deviations in both monetary unions, with average half-lives around 3½ years. The start of EMU did not greatly affect PPP reversion in the euro area. Where changes in nominal exchange rates accounted for the bulk of the adjustment process before 1999, this role was largely taken over by regional inflation differences since. Notwithstanding clear evidence of forward-lookingness in the US, inflation persistence is substantial in both monetary unions.     

Mean reversion in international stock markets: An empirical analysis of the 20th century

This paper analyzes mean reversion in the stock markets of 18 OECD countries during the years 1900–2009. In this period it takes stock prices about 18.5 years, on average, to absorb half of a shock. However, using a rolling-window approach we establish large fluctuations in the speed of mean reversion over time. The highest mean reversion speed is found for the period including the Great Depression and the start of World War II. Furthermore, the early years of the Cold War and the period containing the Oil Crisis of 1973, the Energy Crisis of 1979 and Black Monday in 1987 are also characterized by relatively fast mean reversion. We document half-lives ranging between 2.0 and 22.6 years. Our results suggest that the speed at which stocks revert to their fundamental value is higher in periods of high economic uncertainty, caused by major economic and political events.     

Current account sustainability in the US: What did we really know about it?

We analyze the sustainability of the US current account (CA) deficit by means of unit-root tests. First, we argue that there are several reasons to believe that the CA may follow a non-linear mean-reversion behavior under the null of stationarity. Using a non-linear ESTAR model we can reject the null of non-stationarity favoring the sustainability hypothesis. Second, we ask whether unit-root tests are a useful indicator of sustainability by comparing in-sample results for the 1960–2004 period to the developments observed up to the end of 2008. We find that the non-linear model outperforms the linear and random walk models in terms of forecast performance. The large shocks to the CA observed in the last five years induced a faster speed of mean reversion, ensuring the necessary adjustment to meet the inter-temporal budget constraint.     

Momentum trading,mean reversal and overreaction in Chinese stock market

The vast majority of the literature reports momentum profitability to be overwhelming in the US market and widespread in other countries. However, this paper finds that the pure momentum strategy in general does not yield excess profitability in the Chinese stock markets. We find instead strong mean reversion with an average half-life slightly shorter than 1 year. A pure contrarian investment strategy produces positive excess returns and in general outperforms the pure momentum strategy. Furthermore, momentum may interact with mean reversion. A strategy based on the rolling-regression parameter estimates of the model combining mean reversion and momentum generates both statistically and economically significant excess returns. The combined strategy outperforms both pure momentum and pure contrarian strategies. We conduct a number of robustness tests and confirm the basic findings. Collectively, our results support the overreaction hypothesis.     

Testing for mean reversion in heteroskedastic data II: Autoregression tests based on Gibbs-sampling-augmented randomization

A decade ago Fama and French [Fama, E.G., French, K.R., 1988. Permanent and temporary components of stock prices. J. Political Econ. 96 (2) 246–273] estimated that 40% of variation in stock returns was predictable over horizons of 3–5 yr, which they attributed to a mean reverting stationary component in prices. While it has been clear that the Depression and war years exert a strong influence on these estimates, it has not been clear whether the large returns of that period contribute to the information in the data or rather are a source of noise to be discounted in estimation. This paper uses the Gibbs-sampling-augmented randomization methodology to address the problem of heteroskedasticity in estimation of multi-period return autoregressions. Extending the sample period to 1995, we find little evidence of mean reversion. Examining subsamples, only 1926–1946 provides any evidence of mean reversion, while the post war period is characterized by mean aversion. A test of structural change suggests that this difference between pre and post war periods is significant.     

Combining mean reversion and momentum trading strategies in foreign exchange markets

The literature on equity markets documents the existence of mean reversion and momentum phenomena. Researchers in foreign exchange markets find that foreign exchange rates also display behaviors akin to momentum and mean reversion. This paper implements a trading strategy combining mean reversion and momentum in foreign exchange markets. The strategy was originally designed for equity markets, but it also generates abnormal returns when applied to uncovered interest parity deviations for five countries. I find that the pattern for the positions thus created in the foreign exchange markets is qualitatively similar to that found in the equity markets. Quantitatively, this strategy performs better in foreign exchange markets than in equity markets. Also, it outperforms traditional foreign exchange trading strategies, such as carry trades and moving average rules.     

On the sensitivity of the volume and volatility of bilateral trade flows to exchange rate uncertainty

We present an empirical investigation of the hypotheses that exchange rate uncertainty may have an impact on both the volume and variability of trade flows by considering a broad set of industrial countries' bilateral real trade flows over the period 1980–1998. Similar to the findings of earlier theoretical and empirical research, our first set of results shows that the impact of exchange rate uncertainty on trade flows is indeterminate. Our second set of results provides new and novel findings that exchange rate uncertainty has a consistent positive and significant effect on the volatility of bilateral trade flows, helping us better understand macroeconomic volatility.     

Adjustment patterns to commodity terms of trade shocks: The role of exchange rate and international reserves policies

We analyze the way in which Latin American countries have adjusted to commodity terms of trade (CTOT) shocks in the 1970–2007 period. Specifically, we investigate the degree to which the active management of international reserves and exchange rates impacted the transmission of international price shocks to real exchange rates. We find that active reserve management not only lowers the short run impact of CTOT shocks significantly, but also affects the long run adjustment of REER, effectively lowering its volatility. We also show that relatively small increases in the average holdings of reserves by Latin American economies (to levels still well below other emerging regions current averages) would provide a policy tool as effective as a fixed exchange rate regime in insulating the economy from CTOT shocks. Reserve management could be an effective alternative to fiscal or currency policies for relatively trade closed countries and economies with relatively poor institutions or high government debt. Finally, we analyze the effects of active use of reserve accumulation aimed at smoothing REERs. The result support the view that “leaning against the wind” is potent, but more effective when intervening to support weak currencies rather than intervening to slow down the pace of real appreciation. The active reserve management reduces substantially REER volatility.     

A stochastic dominance analysis of yen carry trades

Yen carry trades have made headline news for over a decade. We examine the profitability of such trades for the period 2001–2009. Yen carry trades generated high mean returns and Sharpe ratios prior to the recent financial crisis. They continued to outperform major stock markets for the full sample period. Given the non-normality of carry trade returns, we apply non-parametric tests based on stochastic dominance (SD) to evaluate whether the high returns of yen carry trades are compatible with risk as reflected in returns on US and global stock market indices. We apply a general test for SD developed recently by Linton, Maasoumi and Whang (2005) to six currencies as well as portfolios of these currencies. For a large class of risk-averse investors, profits from yen carry trades cannot be attributed to risks.     

A re-examination on dissecting the purchasing power parity puzzle

The purpose of this paper is to examine the source of a real exchange-rate adjustment based on the impulse-response function constructed from local projections when the true data-generating process (DGP) is unknown. This work extends the local-projection method proposed by Jordà [2005. Estimation and inference of impulse responses by local projections. American Economic Review 95, 161-182] to allow for variables that are I(1) and exhibit cointegration. Our paper shows that nominal exchange-rate adjustments dominate in the reversion toward PPP regardless of a nominal exchange-rate shock or a price shock. It is also shown that the half-life of real exchange rates is close to that of nominal exchange rates. Since these results are consistent with those of Cheung et al. [Cheung, Y.W., Lai, K.S., Bergman, M., 2004. Dissecting the PPP puzzle: the unconventional roles of nominal exchange rate and price adjustments. Journal of International Economics 64, 135-150], we therefore conclude that their main findings are robust to possible misspecifications in the true DGP.     

Impact of macro-economic surprises on carry trade activity

Can official news and policy announcements affect foreign exchange speculation? A widespread speculative strategy in foreign exchange markets is carry trade. This paper explores the links between macro-economic news and foreign exchange options to identify macro-economic fundamentals most relevant to the pricing of downside risk – measured by risk reversals options contracts – to carry trade activity. Focusing primarily on the Japanese yen carry trade, we identify a significant impact of macro-economic surprises on dollar/yen risk reversals. The effect is sizeable, with news related to bilateral trade balance of particular concern. Moreover, there is a close link between risk reversals and speculative futures positions in Japanese yen. This allows us to quantify a substantial effect of macro-economic news on carry trade activity, with the cost of hedging as the transmission mechanism.     

Real exchange rate adjustment in European transition countries

In single-equation tests, real exchange rates show mean reversion for nine of 10 Central and Eastern European transition countries for the period January 1993 to December 2005. Because of the shift from controlled to market economies and accompanying crises, failed policy regimes and changes in exchange rate regimes, unit root tests for transition countries often require allowance for structural changes. Accounting for structural breaks gives substantially faster mean-reversion speeds than those found for major industrialized countries. These fast adjustment speeds are plausible: Transition countries had perhaps 10 years to make unprecedented adjustments required for accession to the European Union. A number of papers have applied non-linear models to the Central and Eastern European countries. This paper investigates four non-linear models and compares them with piece-wise linear break models. The break models appear superior in detecting mean reversion for the Central and Eastern European transition countries.     

The effectiveness of position limits: Evidence from the foreign exchange futures markets

This study considers the effects of the relative size of hedger and speculator open interests and the potential impact of implementing position limits on the price discovery process in both JPY–USD and EUR–USD futures markets. Hedging trading exerts a negative impact, regardless of its size, on price discovery in futures markets. Hedgers are less likely to be information motivated, so their trading uniformly delays the price discovery process. However, there is a positive and nonlinear impact of speculators’ trade size on price discovery, the contribution of which depends on the relative size of the speculative open interest. Contrary to conventional wisdom among regulators, speculative trading does not harm the market in terms of market efficiency; as long as the percentage of speculators’ open interest is below an endogenously determined threshold (approximately 20% for EUR–USD and 16.3% for JPY–USD), speculative trading even improves futures market efficiency.     

Mean Reversion across National Stock Markets and Parametric Contrarian Investment Strategies

For U.S. stock prices, evidence of mean reversion over long horizons is mixed, possibly due to lack of a reliable long time series. Using additional cross-sectional power gained from national stock index data of 18 countries during the period 1969 to 1996, we find strong evidence of mean reversion in relative stock index prices. Our findings imply a significantly positive speed of reversion with a half-life of three to three and one-half years. This result is robust to alternative specifications and data. Parametric contrarian investment strategies that fully exploit mean reversion across national indexes outperform buy-and-hold and standard contrarian strategies.     

An Analysis of Changes in Specialist Inventories and Quotations

We develop a dynamic model of market making incorporating inventory and information effects. The market maker is both a dealer and an investor, quoting prices that induce mean reversion in inventory toward targets determined by portfolio considerations. We test the model with inventory data from a New York Stock Exchange specialist. Specialist inventories exhibit slow mean reversion, with a half-life of over 49 days, suggesting weak inventory effects. However, after controlling for shifts in desired inventories, the half-life falls to 7.3 days. Further, quote revisions are negatively related to specialist trades and are positively related to the information conveyed by order imbalances.     

Structural breaks in volatility: Evidence for the OECD and non-OECD real exchange rates

This paper attempts to determine whether or not nominal exchange rate regimes affect the volatility of bilateral and effective real exchange rates. To that end, we examine the real exchange rate behaviour for a set of OECD and non-OECD countries during the 1960–2006 period, therefore covering both the Bretton Woods system of fixed exchange rates and the adoption of generalised floating exchange rates from 1973. We make use of an econometric methodology based on the Hansen's (Hansen, B.E., 1997. Approximate asymptotic P values for structural-change tests. Journal of Business and Economic Statistics 15 (1), 60–67) approximation to the p-values of the supreme, exponential and average statistics developed by Andrews (Andrews, D., 1993. Test for parameter instability and structural change with unknown change point. Econometrica 61 (4), 821–856) and Andrews and Ploberger (Andrews, D., Ploberger, W., 1994. Optimal tests when a nuisance parameter is present only under the alternative. Econometrica 62 (6), 1383–1414). This methodology allows us to obtain a profile of p-values and to delimit periods of stability and instability in the variance of real exchange rates. Results suggest that there is clear evidence in favour of the non-neutrality of nominal exchange rate regime regarding real exchange rate volatility for developed countries, but not in the case of developing or emerging countries.     

Local persistence and the PPP hypothesis

This paper examines the statistical properties of the bilateral real exchange rates of the U.S. vs. France, Germany, and the U.K. during the Post-Bretton-Woods period, and draws implications on the Purchasing Power Parity (PPP) hypothesis. Contrary to traditional studies that consider only unit root and stationary processes to describe the real exchange rate behavior, this paper considers an in-between process, the locally persistent process. The empirical results demonstrate the following two findings: (1) Locally persistent processes describe the real exchange rate movements better than unit root and stationary processes, which implies that PPP reversion occurs and PPP holds in the long-run. (2) The confidence intervals for half-life deviations from PPP under local persistence tend to be narrower than those obtained by assuming the ADF and the local-to-unity models.     

Why panel tests of purchasing power parity should allow for heterogeneous mean reversion

Recent studies of purchasing power parity (PPP) use panel tests that fail to take into account heterogeneity in the speed of mean reversion across real exchange rates. In contrast to several other severe restrictions of panel models and tests of PPP, the assumption of homogeneous mean reversion is still widely used and its consequences are virtually unexplored. This paper analyzes the properties of homogeneous and heterogeneous panel unit root testing methodologies. Using Monte Carlo simulation, we uncover important adverse properties of the panel approach that relies on homogeneous estimation and testing. More specifically, power functions are low and assume irregular shapes. Furthermore, homogeneous estimates of the mean reversion parameters exhibit potentially large biases. These properties can lead to misleading inferences on the validity of PPP. Our findings highlight the importance of allowing for heterogeneous estimation when testing for a unit root in panels of real exchange rates.     

Hawkes model for price and trades high-frequency dynamics

We introduce a multivariate Hawkes process that accounts for the dynamics of market prices through the impact of market order arrivals at microstructural level. Our model is a point process mainly characterized by four kernels associated with, respectively, the trade arrival self-excitation, the price changes mean reversion, the impact of trade arrivals on price variations and the feedback of price changes on trading activity. It allows one to account for both stylized facts of market price microstructure (including random time arrival of price moves, discrete price grid, high-frequency mean reversion, correlation functions behaviour at various time scales) and the stylized facts of market impact (mainly the concave-square-root-like/relaxation characteristic shape of the market impact of a meta-order). Moreover, it allows one to estimate the entire market impact profile from anonymous market data. We show that these kernels can be empirically estimated from the empirical conditional mean intensities. We provide numerical examples, application to real data and comparisons to former approaches.     

Purchasing power parity: Modeling and testing mean reversion

A model of mean reversion of exchange rates to purchasing power parity is developed and tested where exchange rates are assumed to follow a mean reverting elastic random walk toward a stochastic PPP rate. The model recognizes the possibility that mean reversion towards PPP may be nonlinear which allows greater flexibility in the adjustment process. Regression equations consistent with the theoretical model are derived. The model is tested using long- and short-term data for six countries. While the results are generally consistent with the findings of previous studies, evidence is presented which demonstrates that the mean reversion process is not linear for some countries.