Am 25.07.2025 um 21:30 schrieb Cottrell, Allin:
It's more specific than I indicated: things go wrong as soon as a
lagged regressor /that is not the last regressor at the time/, gets
omitted.
The regressors will have been reordered, if necessary, at the start of
the backward stepwise procedure, to increase the likelihood that terms
to be omitted will come at the end, which simplifies things
considerably. But that's not going to work 100%. When we have to
eliminate an "internal" column of Q, and row/column of R, the
recomputation that's needed involves reference to the dataset, but at
what starting point? We were diving in at dset->t1, but in a
specification with lags it should be at orig->t1, where @orig is the
original model. That's a distinction without a difference in the case
of cross-sectional data, but it's crucial for time series with
lags.Now that's fixed in git.
Thanks, Allin! I tested with the latest snapshot and everything seems
fine now!
cheers
sven