In this paper Okun's law is tested for the G7 countries in order to co
mpare the responsiveness of unemployment to economic growth. Cyclical
unemployment and output are extracted using Harvey's structural time s
eries model. Okun's coefficient is estimated by OLS, rolling OLS, and
SUR. The coefficient seems to be highest for North America and lowest
for Japan, a result that can be explained in terms of differences in l
abor market rigidities. The rising absolute value of the coefficients
over time indicated by the results of rolling OLS is explained in term
s of labor market reform. (C) 1997 Academic Press.