This paper develops a new covariance-based test of orthogonality that may beattractive when regressors have roots close or equal to unity. In this case standard regression-based orthogonality tests can suffer from (i) size distortions and (ii) uncertainty regarding the appropriate model in which...

This paper studies subsampling hypothesis tests for panel data that are possibly nonstationary, and cross-sectionally correlated and cross-sectionally cointegrated. The tests include panel unit root and cointegration tests as special cases. The number of cross-sectional units in the panel data...

In this paper we propose a general component-driven model to analyze economic data with different characteristics (or regimes) in different time periods. Motivated by empirical data characteristics, our discussion focuses on a simple model driven by a random walk component and a stationary ARMA...

Diba and Grossman (1988) and Hamilton and Whiteman (1985) recommended unit root tests for rational bubbles. They argued that if stock prices are not more explosive than dividends, then it can be concluded that rational bubbles are not present. Evans (1991) demonstrated that these tests will fail...

This paper proposes unit root tests based on partially adaptive estimation. The proposed tests provide an intermediate class of inference procedures that are more efficient than the traditional OLS-based methods and simpler than unit root tests based on fully adaptive estimation using...

In this paper, starting from continuous-time local level unobserved components models for stock and flow data we derive locally best invariant (LBI) stationarity tests for data available at potentially irregularly spaced points in time. We demonstrate that the form of the LBI test differs...

The important concept of purchasing power parity (PPP) has a number of practical implications. Our central objective is to examine the stationarity of Turkey’s real exchange rates to test for the empirical validity of PPP. Our results from conventional univariate unit root tests fail to...