Abstract:
There has been a large literature in recent years, both in Australia and elsewhere, emphasising the importance of testing for unit roots in time series data. In particular, there has been much discussion about whether or not GDP contains a unit root. In this comment, it is pointed out that the importance of this issue has been overstated, and that the implications for macroeconomic theory of the unit root issue are not clear cut. Moreover it is unlikely that the debate over the empirical properties of GDP will be resolved with the sample sizes available.