This article proposes a new diagnostic test for dynamic count models, which is well suited for risk management. Our test proposal is of the Portmanteau-type test for lack of residual autocorrelation. Unlike previous proposals, the resulting test statistic is asymptotically pivotal when...

This article proves the asymptotic efficiency of the Dickey Fuller (DF) test when the Data Generating Process of the variable under consideration is in fact mean stationary with breaks. Monte Carlo simulations show that asymptotic properties remain valid for sample sizes of practical interest....

Regularity conditions are given for the consistency of the Poisson quasi-maximum likelihood estimator of the conditional mean parameter of a count time series. The asymptotic distribution of the estimator is studied when the parameter belongs to the interior of the parameter space and when it...

Whilst the existence of a unit root implies that current shocks have permanent effects, in the long run, the simultaneous presence of a deterministic trend obliterates that consequence. As such, the long-run level of macroeconomic series depends upon the existence of a deterministic trend. This...

This paper presents Rtadf (Right Tail Augmented Dickey-Fuller), an EViews Add-in that facilitates the performance of time series based tests that help detect and date-stamp asset price bubbles. Detection strategy is based on a right-tail variation of the standard Augmented Dickey-Fuller (ADF)...

This paper explores relative price convergence for 18 cities in Turkey. The convergence implies stationarity in the long run. Henceforth, to observe whether price convergence occurs or not, this study conducts unit root tests following Lee and Strazicich (2003) with two structural breaks in...

This paper proposes a new testing procedure for the degree of fractional integration of a time series inspired on the unit root test of Dickey-Fuller (1979). The composite null hypothesis is that of d=d0 against d<d0. The test statistics is the same as in Dickey-Fuller test, exploiting the fact that if the process, under study, is I(d0) then the (-1+d0)th differenced series is I(1) under the null d=d0. If d>=d0, using the generalization of Sowell's results (1990), we propose a test based...</d0.>

This paper considers the statistical inference of the class of asymmetric power-transformed GARCH(1,1) models in presence of possible explosiveness. We study the explosive behavior of volatility when the strict stationarity condition is not met. This allows us to establish the asymptotic...

Spurious regression phenomenon has been recognized for a wide range of Data Generating Processes: driftless unit roots, unit roots with drift, long memory, trend and broken-trend stationarity, etc. The usual framework is Ordinary Least Squares. We show that the spurious phenomenon also occurs in...