In this paper we analyze the sensitivity of unit root inference to nonlinear transformations through Bayesian techniques. We make joint inference about the Box-Cox transformation, which includes the cases yt and log(yt), and the unit root. When we apply our method to the fourteen Nelson-Plosser...

We propose methods to test for common deterministic seasonality, while allowing for possible seasonal unit roots. For this purpose, we consider panel methods, where we allow for individualand for common dynamics. To decide on the presence of seasonal unit roots, we introduce a decision-based...

We use Greek data during 1960-1994 to test and estimate a model in which wage inflation, price inflation and unemployment depend on the exchange rate regime, the identity of the political party in power and whether an election is expected to take place.

This study analyzes the size and power of tests of the null of stationarity against the unit root alternative. Existing evidence is limited to processes with roots between 0 and 0.7. In sharp contrast, virtually all applications of economic interest involve null hypotheses much closer to 1. We...

This paper considers the problem of testing for a nonstochastic seasonal unit root in a seasonally observed time-series process against the alternative of a randomized seasonel root with mean unity; that is, the process displays heteroscedastic seasonal integration.