This paper proposes a new time-domain test of a process being I(d), 0 d = 1, under the null, against the alternative of being I(0) with deterministic components subject to structural breaks at known or unknown dates, with the goal of disentangling the existing identification issue between...

The paper analyzes the impact of the initial observation on the problem of testing for unit roots. To this end, we derive a family of optimal tests that maximize a weighted average power criterion with respect to the initial observation. We then investigate the relationship of this optimal...

We consider a number of unit root tests for micro panels where the number of individuals is typically large, but the number of time periods is often very small. As we discuss, the presence of a unit root is closely related to the identification of parameters of interest in this context....

A novel simulation based approach to unit root testing is proposed in this paper. The test is constructed from the distinct orders in probability of the OLS parameter estimates obtained from a spurious and an unbalanced regression, respectively. While the parameter estimate from a regression of...

When monetary policy has an explicit inflation target, observed inflation should be a stationary process. In countries where, for a variety of reasons, the determinants of inflation could lead it to follow a non-stationary process, the adoption of an inflation targeting framework should...

This paper assesses whether the economy of East Germany is catching up with the West German region in terms of welfare. While the primary measure for convergence and catching up is per capita output, we also look at other macroeconomic indicators such as unemployment rates, wage rates, and...

Recent research has found evidence that supports the purchasing power parity (PPP) condition in developed countries using very long-span data, while evidence for developing countries is almost nonexistent. This paper tries to fulfill this void by testing the validity of PPP as a long run...

The Perron test is the most commonly applied procedure to test for a unit root in the presence of a structural break of unknown timing in the trend function. Deriving the Perron-type test regression from an unobserved component model, it is shown that the test regression in fact is nonlinear in...

This paper examines the major sources of economic growth in Iran using annual time series data (1960 to 2003). The time series properties of the data are analysed by Perron’s innovational outlier and additive outlier models. The empirical results based these models show that there is not...

Applications of panel unit root tests have become commonplace in empirical economics, yet there are ambiguities as how best to interpret the test results. This note clarifies that rejection of the panel unit root hypothesis should be interpreted as evidence that a statistically significant...