First of all I would like to express most sincere thanks to everybody
who answered on the matter. All gretl users must have seen this very
fine result of scripting and it’s rare to receive fast and quality
help and get exactly what you were looking for when dealing with
econometric packages. Allin and Jack – I may become your fan.
I have made a few modifications to the script such as:
1. Cost was scaled the same way as Price (it’s measured in the same
units in the dataset)
2. Possible values of mu and sigma changed and the results are still
quite consistent with the conventional theory .18<mu<.5
.01<sig<.041
3. The line for optimal mu and sigma remain and non-optimal deleted in
order to avoid confusion
A question: why estimate ‘y – GDV’ and not ‘y’ as a dependent
variable. I understand that it’s equivalent in the linear regression
just want to know the reason for this.
The problem with the script is - NLS isn’t estimated if FE = 1 because
series u = $unit doesn’t work with the current periodicity. Some
pointers on how to solve this would be nice.
Another problem I encountered is my little knowledge of the NLS
estimation process – I can’t figure out how Jack uses linear
combinations, nelem function and covarince matrix to get the NLS
results. If somebody could recommend me some scientific articles or a
good advanced textbook that covers the technique similar to the one
used in the script it would definitely help.
Regards,
Gregory
On Sat, Jan 29, 2011 at 6:33 PM, Riccardo (Jack) Lucchetti
<r.lucchetti(a)univpm.it> wrote:
On Sat, 29 Jan 2011, Riccardo (Jack) Lucchetti wrote:
> On Sat, 29 Jan 2011, Allin Cottrell wrote:
>
>> On Sat, 29 Jan 2011, Allin Cottrell wrote:
>>
>>> I've had one more go at this problem, because it seems like quite
>>> a nice showcase for what one can now do with gretl scripting.
>>
>> I should have said: the NLS portion of my combined script is
>> shamelessly plundered from Jack Lucchetti's posting.
>
> No problem: in fact, I quite like this game. Minimal improvement attached.
And while we're at it: a little poolability test.
Riccardo (Jack) Lucchetti
Dipartimento di Economia
Università Politecnica delle Marche
r.lucchetti(a)univpm.it
http://www.econ.univpm.it/lucchetti
_______________________________________________
Gretl-users mailing list
Gretl-users(a)lists.wfu.edu
http://lists.wfu.edu/mailman/listinfo/gretl-users