Time series from fifteen OECD countries for the period 1870–1994 are examined to determine if per capita incomes are stochastically converging. To perform our tests, we utilize a minimum Lagrange multiplier unit root test that endogenously determines two structural breaks in level and trend. In contrast to other tests, our test is not subject to rejections of the null in the presence of a unit ...

Xuan Leng1 and Liang Peng2 Abstract. Motivated by a recent discovery that the two-step inference for Lee-Carter mortality model is inconsistent when the mortality index does not follow from a nearly integrated AR(1) process, we propose a test for unit root in a Lee-Carter model with an AR(2) process for the mortality index. Although testing for a unit root has been studied extensively in econom...

The research of Kim and Schmidt (1993) is extended to examine the properties of asymmetric unit root tests in the presence of generalised autoregressive conditional heteroskedasticity (GARCH). Using Monte Carlo simulation, threshold autoregressive and momentum—threshold autoregressive asymmetric unit tests are shown to suffer greater size distortion than the original (implicitly symmetric) Dick...

A growing literature analyzes determinants of insurance prices using time series data on insurer underwriting margins. If the variables analyzed are stationary, conventional regression models may be appropriately used to test hypotheses. Based on pre-tests for a unit root, several studies have instead used cointegration analysis to analyze the long run relationship between purportedly non-stati...

In practice a degree of uncertainty will always exist concerning what specification to adopt for the deterministic trend function when running unit root tests. While most macroeconomic time series appear to display an underlying trend, it is often far from clear whether this component is best modelled as a simple linear trend (so that long-run growth rates are constant) or by a more complicated...

Countries consume large amounts of coal, oil, and natural gas due to the energy structure dominated by fossil fuels worldwide. For this reason, rate renewable energies in countries or country groups general is below global average level. In study, we aimed test stationarity consumption for Brazil, Russia, India, China, South Africa, Turkey (the BRICS-T countries), which are a rapid development....

This paper extends the cross sectionally augmented panel unit root test proposed by Pesaran (2007) to the case of a multifactor error structure. The basic idea is to exploit information regarding the m unobserved factors that are shared by k other time series in addition to the variable under consideration. Initially we develop a test assuming that m, the true number of factors is known, and sh...

We propose a unit root test for panels with cross-sectional dependency. We allow general dependency structure among the innovations that generate data for each of the cross-sectional units. Each unit may have di)erent sample size, and therefore unbalanced panels are also permitted in our framework. Yet, the test is asymptotically normal, and does not require any tabulation of the critical value...

objectives: gingival recession can lead to root exposure and discomfort for patients. there are various techniques for root coverage. the aim of this study was to compare the use of gingival unit graft (palatal graft including the marginal gingiva and papillae) with free gingival graft for treatment of localized gingival recession. materials and methods: in this randomized controlled clinical t...