This paper exploits the fact that any time series with a unit root can de decomposed into a stationary series and a random walk. Since the random walk component can have arbitrarily small variance, tests for unit roots or trend stationarity have arbitrarily low power in finite samples. Furthermore, there are unit root processes whose likelihood functions and autocorrelation functions are arbitr...

in this paper, we analyze the dynamics of income gap between 138 countries with usa by using time series model of convergence hypothesis and various panel unit root tests over period 1950-2008. all panel unit root tests don’t reject the null hypothesis of unit root. univariate unit root tests results show that gdp per capita of south korea, switzerland, austria, lesoto and hungry catch up with ...

In cointegration analysis, it is customary to test the hypothesis of unit roots separately for each single time series. In this note, we point out that this procedure may imply large size distortion of the unit root tests if the DGP is a VAR. It is well-known that univariate models implied by a VAR data generating process necessarily have a finite order MA component. This feature may explain wh...

the main objective of this case report is to present a rare root canal configuration of maxillary molar with seven root canals; three mesiobuccal, two palatal and two distobuccal canals diagnosed during treatment procedure confirmed by spiral computed tomography. a thorough knowledge of root canal morphology, proper clinical and radiographic examination, and use of dental operating microscopes ...

This essay introduces a new featured section, to be published in Small Axe annually, that explores the critical vocabulary of field Caribbean studies.

Although the impacts of structural instability on testing for unit root have been studied extensively for univariate time series, such impacts on panel data unit root tests are still relatively unknown. A major issue is the choice of model in accommodating different types of break (instability) prior to testing for unit root. Specifically, researchers must specify a potential break in the inter...