This study first reexamines the findings of Perron (1989) regarding th
e claim that most macroeconomic time series are best construed as stat
ionary fluctuations around a deterministic trend function if allowance
is made for the possibility of a shift in the intercept of the trend
function in 1929 (a crash) and a shift in slope in 1973 (a slowdown in
growth). Unlike that previous study, the date of possible change is n
ot fixed a priori but is considered as unknown. We consider various me
thods to select the break points and the asymptotic and finite sample
distributions of the corresponding statistics. A detailed discussion a
bout the choice of the truncation lag parameter in the autoregression
and of its effect on the critical values is also included. Most of the
rejections reported in Perron (1989) are confirmed using this approac
h. Secondly, this paper investigates an international data set of post
-war quarterly real GNP (or GDP) series for the G-7 countries. Our res
ults are compared and contrasted to those of Banerjee et al. (1992) an
d Zivot and Andrews (1992). In contrast to the theoretical results con
tained in these papers, we derive the limiting distribution of the seq
uential test without trimming. (C) 1997 Elsevier Science S.A.