This paper derives the asymptotic distribution of the nonparametric neural network estimator of the Lyapunov exponent in a noisy system. Positivity of the Lyapunov exponent is an operational definition of chaos. We introduce a statistical framework for testing the chaotic hypothesis based on the...

This paper proposes a test for the correct specification of a dynamic time-series model that is taken to be stationary about a deterministic linear trend function with no more than a finite number of discontinuities in the vector of trend coefficients. The test avoids the consideration of...

The framework of stationarity testing is extended to allow a generic smooth trend function estimated nonparametrically. The asymptotic behavior of the pseudo-Lagrange Multiplier test is analyzed in this setting. The proposed implementation delivers a consistent test whose limiting null...

Deciding whether a time series that appears nonstationary is in fact fractionally integrated or subject to structural change is a diffcult task. However, various tests have recently been introduced for distinguishing long memory from level shifts and nonlinearity. In this paper, three testing...

The purpose in this letter is first to review briefly the empirical results on the relationship between real interest rates and real exchange rates; this empirical literature provides little support for the hypothesis of Roll that expected real interest rates are equal in general. Our second aim...

In this paper we introduce a new nonlinear Markov-STAR model to capture both the markov switching and smooth transition dynamics for real exchange rates. The Markov switching part captures the effect of time variations of the equilibrium exchange rates, while the smooth transition part models...

We suggest that the real exchange rate between the major currencies in the post-Bretton Woods period can be described by a stationary, two state Markov switching AR(1) model. Based on the forecast performance, both in-sample and out-of-sample, we find that this model out-performs two competing...

This paper considers testing the unit root hypothesis against a smooth transition autoregressive model as the alternative. The model specification makes it possible to discriminate between nonstationary random walk and stationary nonlinear processes. Some new limit results are presented,...

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...