Previous studies have included other variables such
as cellaring potential, year of marketing and producer
size (see, e.g. Oczkowski 1994). We did not have such
variables available for our full time series, so cannot
expect as high an adjusted R
2
value.
6
There are 765 (923) different producers in the
Halliday (
Winestate
) sample for Australia. For New
Zealand, there are 203 (205) different producers in the
Halliday (Winestate) data set.