a survey of unit root theory with an emphasis on testing principles and recent developments. The general framework … adopted makes it possible to consider tests of stochastic trends against trend stationarity and trend breaks of a general type … theory. Some simulation results are reported, and an extensive list of references and an annotated bibliography are provided. …

Trends are ubiquitous in economic discourse, play a role in much economic theory, and have been intensively studied in … theory about the source and nature of trend behavior, even less guidance about practical formulations, and are heavily …

A method for assessing the degree of non-stationarity in annual wind speed records is presented. The method uses … quantitative tests on the wind speed records to assess the length of the period over which an assumption of stationarity in the … wind record can be considered to provide reasonable engineering accuracy. The tests evaluate stationarity in second moment …