http://repub.eur.nl/res/aut/7725/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/22283/ 2011-02-01T00:00:00Z 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. http://repub.eur.nl/res/pub/21024/ 2010-10-01T00:00:00Z Abstract 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. http://repub.eur.nl/res/pub/8066/ 2006-10-26T00:00:00Z Ben Tims was born on 9 November 1975 in Rotterdam, the Netherlands. From 1994 till 1999 he studied econometrics at the Erasmus University Rotterdam. From September 1999 to December 2004 he has been a PhD student at the Financial Management department of the Rotterdam School of Management at Erasmus University Rotterdam. Since January 2005 he has been assistant professor at the same department. His research interests focus primarily on the dynamics on exchange rates. http://repub.eur.nl/res/pub/7173/ 2005-12-19T00:00:00Z This paper analyzes the properties of multivariate tests of purchasing power parity (PPP) that fail to take heterogeneity in the speed of mean reversion across real exchange rates into account. We compare the performance of homogeneous and heterogeneous unit root testing methodologies. The recent literature has successfully contested several severe restrictions on the structure of the model, but the assumption of homogeneous mean reversion is still widely used and its consequences are virtually unexplored. Using Monte Carlo simulation, we uncover important adverse properties of the methodology 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. This can have a dramatic impact on inferences made on the validity of the PPP hypothesis. Our findings highlight the importance of allowing for heterogeneous estimation when testing for a unit root in panels of real exchange rates. http://repub.eur.nl/res/pub/16942/ 2004-11-01T00:00:00Z This paper analyzes purchasing power parity (PPP) for the euro area. We study the impact of the introduction of the euro in 1999 on the behavior of real exchange rates. We test the PPP hypothesis for a panel of real exchange rates within the euro area over the period 1973–2003. Our methodology exploits the cross-sectional dependence across real exchange rates and allows for heterogeneity in the rates of mean reversion. We present evidence in favor of PPP for the full panel of real exchange rates, but we show that accounting for cross-country differences within the euro area is essential. The unit root hypothesis can be rejected for some real exchange rates, but evidence for PPP is weak for others. We also investigate PPP between the ‘‘synthetic’’ euro against several other major currencies over the period 1979–2003. We find support for the PPP hypothesis for the full panel of real exchange rates. When the restriction of a common mean reversion coefficient is relaxed, we reject the unit root hypothesis for the euro-Swiss franc rate only. We conclude that the process of economic integration in Europe has accelerated convergence toward PPP within the euro area. http://repub.eur.nl/res/pub/1442/ 2004-08-06T00:00:00Z This paper analyzes purchasing power parity (PPP) for the euro area. We study the impact of the introduction of the euro in 1999 on the behavior of real exchange rates. We test the PPP hypothesis for a panel of real exchange rates within the euro area over the period 1973-2003. Our methodology exploits the cross-sectional dependence across real exchange rates and allows for heterogeneity in the rates of mean reversion. We present evidence in favor of PPP for the full panel of real exchange rates, but we show that accounting for cross-country differences within the euro area is essential. The unit root hypothesis can be rejected for some real exchange rates, but evidence for PPP is weak for others. We also investigate PPP between the “synthetic” euro against several other major currencies over the period 1979-2003. We find support for the PPP hypothesis for the full panel of real exchange rates. When the restriction of a common mean reversion coefficient is relaxed, we reject the unit root hypothesis for the euro-Swiss franc rate only. We conclude that the process of economic integration in Europe has accelerated convergence toward PPP within the euro area. http://repub.eur.nl/res/pub/282/ 2003-03-10T00:00:00Z In this paper we present a parsimonious multivariate model for exchange rate volatilities based on logarithmic high-low ranges of daily exchange rates. The multivariate stochastic volatility model divides the log range of each exchange rate into two independent latent factors, which are interpreted as the underlying currency specific components. Due to the normality of logarithmic volatilities the model can be estimated conveniently with standard Kalman filter techniques. Our results show that our model fits the exchange rate data quite well. Exchange rate news seems to be very currency-specific and allows us to identify which currency contributes most to both exchange rate levels and exchange rate volatilities. http://repub.eur.nl/res/pub/276/ 2003-03-04T00:00:00Z In this paper we analyze the impact of the investment horizon on international port-folio choice. We approach this issue by considering whether or not an investor shouldadd investments from other countries to an existing portfolio. The statistical teststhat we employ (spanning tests) are based on whether or not the investment spacecan significantly be expanded within a mean-variance framework. Our results indi-cate that for a U.S. based investor with a mean-variance utility function diversifyingtowards other countries and asset classes depends on the investment horizon. This holds especially for portfolios that originally consist of investments in bonds.