While it is widely agreed that Purchasing Power Parity (PPP) holds as a long-run concept the specific dynamic driving the process is largely build upon a priori economic belief rather than a thorough statistical modeling procedure. The two prevailing time series models, i.e. the exponential...

A simple procedure for the specification of the transition function describing the regime switch in nonlinear autoregressive models is proposed. This procedure is based on auxiliary regressions of unit root tests and is applicable to a variety of transition functions. In contrast to other...

The well-known problem of too many instruments in dynamic panel data GMM is dealt with in detail in Roodman (2009, Oxford Bull. Econ. Statist.). The present paper goes one step further by providing a solution to this problem: factorisation of the standard instrument set is shown to be a valid...

We consider the problem of forecasting time series with long memory when the memory parameter is subject to a structural break. By means of a large-scale Monte Carlo study we show that ignoring such a change in persistence leads to substantially reduced forecasting precision. The strength of...

Nowadays foreign exchange interventions occur in emerging market economies whereas empirical studies on interventions mainly refer to advanced economies. However, interventions in emerging markets are different from those in advanced economies: they occur regularly and central banks have...

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...

Today´s derivative pricing base on stochastic models developed in the 70´s. These models base on some unrealistic assumptions. The system Warrant Pro 1 presented here combines the software agent PISA (Partially Intelligent Software Agent) and the neurosimulator FAUN (Fast Approximation with...

The volatility of exchange rates is of high importance, because it affects decisions of market participants. The choice of the exchange rate arrangement affects the volatility of the exchange rate: higher flexibility goes ahead with increasing volatility and vice versa. We investigate the...

We study the relationship between foreign exchange trading activity and volatility on the USD/EUR foreign exchange market on the basis of a unique data set around the events of 09/11/2001. We find that volatility and bid-ask spreads are by far larger at that time, but the shock is not...

Early warning systems (EWSs) are subject to restrictions that apply to exchange rates in general: fundamentals matter but their influence is small and unstable. Despite this limitation four major lessons emerge: First, EWSs have robust forecasting power and thus help policy-makers to prevent...