This paper studies the behavior of the HEGY statistics for quarterly data, for seasonal autoregressive unit roots, when the analyzed time series is deterministic seasonal stationary but exhibits a change in the seasonal pattern. As a by-product we analyze also the HEGY test for the nonseasonal...

Single index models are frequently used in econometrics and biometrics. Logit and Probit models are special cases with fixed link functions. In this paper we consider a bootstrap specification test that detects nonparametric deviations of the link function. The bootstrap is used with the aim to...

We establish sufficient conditions on durations that are stationary with finite variance and memory parameter $d \in [0,1/2)$ to ensure that the corresponding counting process $N(t)$ satisfies $\textmd{Var} \, N(t) \sim C t^{2d+1}$ ($C0$) as $t \rightarrow \infty$, with the same memory parameter...

Building on the work of Lustbader and Moolgavkar (1985, 'A Diagnostic Statistic for the Score Test', Journal of the American Statistical Association 80, 375-379), this paper studies influence diagnostics for score tests. The diagnostic proposed by Lustbader and Moolgavkar is reassessed and...

For hundred years the future was occupying the persons. The ancient Greeks, the Romans, the Egyptians, the Indians, the Chinese and other great ancient cultures, but also the modern, as the English, Germans and the Americans and with the help of the development of technology and computers they...

Edgeworth expansions to the null distributions of three classical test statistics in the multivariate regression model were derived by Rothenberg (1977) and Phillips (1984) with the purpose of obtaining size-corrected critical values for such tests. We combine their results with the results of...

The universal method for testing linearity against smooth transition autoregressive (STAR) alternatives is the linearization of the STAR model around the null nuisance parameter value, and performing F-tests on polynomial regressions in the spirit of the RESET test. Polynomial regressors,...

We consider the power of unit root tests for different deviations of the initial observation from the deterministic component of the series. Following recent work highlighting the relative power performance of extant tests, we propose a new procedure based on a data-dependent weighted average of...

Duration dependent Markov-switching VAR (DDMS-VAR) models are time series models with data generating process consisting in a mixture of two VAR processes, which switches according to a two-state Markov chain with transition probabilities depending on how long the process has been in a state. In...

We develop and apply a set of hypothesis tests with which to study changes in the angular distribution of points in delay space. Crack and Ledoit (1996) plotted daily stock returns against themselves with one day's lag. The graph shows these points collected along several rays from the origin....