This paper suggests that the relevant question concerning unit root' in the U.S. real GNP time series pertains to the relative importance of difference-stationary and trend-stationary components. Vari
We use the revised estimates of U.S. GNP constructed by Christina Romer (1989) to assess the time-series properties of U.S. output per capita over the past century. We reject at conventional significa
This paper proposes a class of procedures that consistently classify the stochastic component of a time series as being integrated either of order zero (l(0 or one (l(1 for general 1(0) and 1(1) proce
