On Tue, 12 Oct 2010, Marcin B�^Bażejowski wrote:
[ script that compares adf results with and without the --gls
option ]
Fixed in CVS. The problem was related to something Sven mentioned
lately, namely the "reach-back" to pre-sample values. This was
definitely too liberal with adf --gls, for the regression that
estimates the GLS parameters.
One thing to note is that your commands to generate an AR(1)
process were not optimal:
series y = 10
series u = normal(0,1)
genr y = 0.1*y(-1) + u
This is rather slow, and requires a "lead in" period before the
steady state is attained (which is what tripped up adf). You're
better using the filter() function:
series u = normal(0,1)
series y = filter(u, 1, 0.1, 10)
Allin