Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper examines whether output per capita in 126 countries is better described as trend or difference stationary, using appropriate finite-sample critical values. Depending upon whether one uses solely a test with a trend stationary null, or solely one with a difference stationary null, very different conclusions are obtained. This outcome suggests that it is useful to consider the tests complementary, rather than competing. The authors find that, when a definite characterization of GDP can be made, it is very likely to indicate a difference stationary process. However, the likelihood of making definite conclusions does vary positively with both income level and data quality. Copyright 1996 by Royal Economic Society.