Monthly time-series data based on agricultural commodities tend to present strong and particular patterns of seasonality. The presence of zero values in some of the seasons is not explained by the absence of reporting but is the result of actual features of agricultural processes. Seasonal unit...

Testing for unit roots in short-term interest rates plays a key role in the empirical modelling of these series. It is widely assumed that the volatility of interest rates follows some time-varying function which is dependent of the level of the series. This may cause distortions in the...

This paper introduces a new confidence interval (CI) for the autoregressive parameter (AR) in an AR(1) model that allows for conditional heteroskedasticity of general form and AR parameters that are less than or equal to unity. The CI is a modification of Mikusheva's (2007a) modification of...

This paper analyzes and employs two versions of the Functional Central Limit Theorem within the framework of a unit root with a structural break. Initial attention is focused on the probabilistic structure of the time series to be considered. Later, attention is placed on the asymptotic theory...

This paper shows that the evolution of the level of Mexico real and real per capita output between 1895 and 2008 can be adequately described through a trendstationary model, affected by 4 structural breaks, which occurred at dates that seem to coincide with domestic institutional arrangements,...

This paper presents the R implementation of the panel covariate augmented Dickey-Fuller (panel-CADF) test proposed in Costantini and Lupi (2011), as well as the implementation of the tests advocated in Choi (2001) and Demetrescu, Hassler, and Tarcolea (2006). A panel-CADF extension of the test...

In this paper, we re-examine stationarity of the Australian real exchange rate (RER). For this purpose, we modify the test of Kapetanios et al. [Testing for a unit root in the nonlinear STAR framework. Journal of Econometrics 112 (2003), 359-379] to allow for a nonlinear trend function in the...

This paper develops a simple test for the null hypothesis of no unit root for panel data with cross-sectional dependence in the form of a common factor in the disturbance. We do not estimate the common factor but mop-up its effect by employing the same method as the one proposed in Pesaran...

Most empirical evidence suggests that the efficient futures market hypothesis, henceforth referred to as EFMH, stating that spot and futures prices should cointegrate with a unit slope on futures prices, does not hold, a finding at odds with many theoretical models. This paper argues that these...

We show that the use of generalized least squares (GLS) detrending procedures leads to important empirical power gains compared to ordinary least squares (OLS) detrend- ing method when testing the null hypothesis of unit root for bounded processes. The non-centrality parameter that is used in...