This paper proposes a standard for notation in econometrics. It presents a fully integrated and internally consistent framework for notation and abbreviations, which is as close as possible to existing common practice. The symbols used are instantly recognizable and interpretable, thus...

In the context of regression-based (quarterly) seasonal unit root tests, we examine the impact of initial conditions (one for each quarter) of the process on test power. We investigate the behaviour of the well-known OLS detrended HEGY seasonal unit root tests together with their...

In this paper we consider the problem of testing the null hypothesis that a series has a constant level (possibly as part of a more general deterministic mean) against the alternative that the level follows a random walk. This problem has previously been studied by, inter alia, Nyblom and...