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Re: st: example about choice experiment datasheet


From   elisabetta capobianco <elisabetta.capobianco@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: example about choice experiment datasheet
Date   Sat, 24 Nov 2012 17:04:41 +0100

Thank you Arne, I have taken the book.
My problem is that I have 16 scenarios for id (n=131) with 4 different
alternatives for each scenario .
So in the dataset I have written for each id non 4 alternatives
(1,2,3,4) but 64 alternatives. Is it correct?



id   scenario      alt
1         1            1
1         1            2
1         1             3
1         1            4
1         2            5(or1?)
1         2            6(or2?)
1         2            7(or3?)
1         2            8 (or4?)
1         3            9(or1?)
.
.
.
.
.
1         16           64
2         1              1
.
.
And when I wrote:
asclogit choice organic price, case(id) alternatives(car) noconst

case is id or scenario? I suppose scenario. But if is scenario I don't
know how to use id!
And alternatives are the 64 alternatives?


Thank you so much for your help.

elisabetta





2012/11/23 Arne Risa Hole <arnehole@gmail.com>:
> Elisabetta
>
> I am fairly sure that you can use -asclogit- to do what you want. If
> you don't want alternative-specific constants you can use the
> -noconst- option. Modifying the example in the help-file slightly:
>
> webuse choice
> asclogit choice dealer, case(id) alternatives(car) noconst
>
> As you can see the only coefficient which is estimated in this case is
> the one for the dealer attribute, which is analogous to the organic
> and price attributes in your experiment. In your case the variable
> that identifies the alternatives for each case ("car" in the example)
> can simply take the values 1, 2, 3 and 4 since your alternatives are
> unlabelled.
>
> I also recommend taking a look at a basic choice modelling text before
> proceeding, such as
> http://books.google.co.uk/books/about/Applied_Choice_Analysis.html?id=8yZrtCCABAgC.
>
> Good luck!
>
> Arne
>
> On 23 November 2012 13:25, elisabetta capobianco
> <elisabetta.capobianco@gmail.com> wrote:
>> I think that asclogit is not the right comand for me.
>> Because I have 4 unlabeled alternatives, 16 diferrent scenarios with 4
>> alternatives for 131 individuals. So my indipendent viariables are the
>> attributes and dipendent variables the utility for each level of
>> attribute.
>> I need to know the importance of every level, not of alternatives.
>> Ex.:n=131
>> scenario 1)   A       B        C         D
>>      organic  org   no org   no org   org
>>      price       4         8         4         4
>> scenario 2)   A      B         C        D
>>     organic  no org  no org   org     no org
>>       price     12     16         8        8
>> .
>> .
>> .
>> Perhaps with mixlogit? Because the example is on a specific
>> alternative, car or bus.
>> I instead need to know the coefficient of attributes and levels.
>>
>> I don't know if I have explained well, I hope!
>>
>> e
>>
>>
>>
>> 2012/11/23 Arne Risa Hole <arnehole@gmail.com>:
>>> -help asclogit_postestimation-
>>>
>>> Arne
>>>
>>> On 23 November 2012 11:05, elisabetta capobianco
>>> <elisabetta.capobianco@gmail.com> wrote:
>>>> Dear Arne,
>>>> i need to estimate the marginal effect of levels on attributes of my choice.
>>>> Is it possible?
>>>> es:
>>>> about meat:
>>>> attribute   level
>>>> label        organic/not organic
>>>> origin       local abroad
>>>> prize        4/8
>>>>
>>>> I would know the utility for each level of each attribute.
>>>>
>>>> Thank you!
>>>> elisabetta
>>>>
>>>>
>>>>
>>>> 2012/11/21 elisabetta capobianco <elisabetta.capobianco@gmail.com>:
>>>>> Thank you so much Arne!!!
>>>>> I'm creating the data set and then i'll try to run in Stata!
>>>>>
>>>>> Elisabetta
>>>>>
>>>>> 2012/11/20 Arne Risa Hole <arnehole@gmail.com>:
>>>>>> Elisabetta
>>>>>>
>>>>>> -mlogit- is not very useful to model data from choice experiments as
>>>>>> it does not allow alternative-specific explanatory variables.
>>>>>> -asclogit- requires your data to be in long form (one row per
>>>>>> alternative); see -help asclogit- and the first example in the paper I
>>>>>> mentioned in my last email.
>>>>>>
>>>>>> Arne
>>>>>>
>>>>>> On 20 November 2012 10:04, elisabetta capobianco
>>>>>> <elisabetta.capobianco@gmail.com> wrote:
>>>>>>> Thank you Arne, I want to use asclogit and mlogit for my choice modelling.
>>>>>>>
>>>>>>>
>>>>>>> 2012/11/19 Arne Risa Hole <arnehole@gmail.com>:
>>>>>>>> Elisabetta
>>>>>>>>
>>>>>>>> As Jay says the correct data form depends on the estimation command
>>>>>>>> you are planning to use, so this is a very important piece of
>>>>>>>> information that you haven't given us. You may find the examples in
>>>>>>>> http://www.stata-journal.com/article.html?article=st0133 useful.
>>>>>>>> Generally speaking the best strategy is to import the data into Stata
>>>>>>>> and then use commands like -reshape- to convert the data into the form
>>>>>>>> you want, rather than trying to do this in Excel.
>>>>>>>>
>>>>>>>> Arne
>>>>>>>>
>>>>>>>>> On 19 November 2012 15:51, elisabetta capobianco
>>>>>>>>> <elisabetta.capobianco@gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>> Thank you for your answer!
>>>>>>>>>> I want to do a mixed logit, but I have found a data set on help file
>>>>>>>>>> with just one choice set. I have 16 choice sets and I don't know how
>>>>>>>>>> to fil the excel data set.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> 2012/11/18 JVerkuilen (Gmail) <jvverkuilen@gmail.com>:
>>>>>>>>>> > On Sun, Nov 18, 2012 at 4:11 AM, elisabetta capobianco
>>>>>>>>>> > <elisabetta.capobianco@gmail.com> wrote:
>>>>>>>>>> >> Hi, I'm new of statalist and stata!
>>>>>>>>>> >> I'm working on choice experiment about food preferences in schools.
>>>>>>>>>> >> I have 4 alternatives unlabelled, 4 attributes and 4 levels, 130
>>>>>>>>>> >> individuals.
>>>>>>>>>> >> I have the data base in excel, but before insheet the file in stata
>>>>>>>>>> >> i'm not sure that i have put the data in the right mode in the excel
>>>>>>>>>> >> file.
>>>>>>>>>> >> Have you got an example on a excel datasheet about choice modelling?
>>>>>>>>>> >> Just an example to understand how to organize my datasheet.
>>>>>>>>>> >
>>>>>>>>>> > It depends on what analysis you want to use. -clogit- and procedures
>>>>>>>>>> > like it that are using alternative-specific predictors use the same
>>>>>>>>>> > basic format, which is specified in the help file. You can see the
>>>>>>>>>> > example dataset there. Essentially it is a "long" format like
>>>>>>>>>> > person-period in a growth model with time-varying covariates.
>>>>>>>>>> > *
>>>>>>>>>> > *   For searches and help try:
>>>>>>>>>> > *   http://www.stata.com/help.cgi?search
>>>>>>>>>> > *   http://www.stata.com/support/faqs/resources/statalist-faq/
>>>>>>>>>> > *   http://www.ats.ucla.edu/stat/stata/
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Rispetta l'ambiente: se non ti è necessario, non stampare questa mail
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>           Le informazioni contenute in questa comunicazione e gli
>>>>>>>>>> eventuali documenti allegati
>>>>>>>>>>
>>>>>>>>>>           hanno carattere confidenziale e sono a uso esclusivo del
>>>>>>>>>> destinatario. Nel caso
>>>>>>>>>>
>>>>>>>>>>           questa comunicazione Vi sia pervenuta per errore, Vi informo
>>>>>>>>>> che la sua diffusione
>>>>>>>>>>
>>>>>>>>>>           e riproduzione è contraria alla legge e prego di darmi
>>>>>>>>>> prontamente avviso
>>>>>>>>>>
>>>>>>>>>>           e di cancellare quanto ricevuto. Grazie.
>>>>>>>>>>
>>>>>>>>>> *
>>>>>>>>>> *   For searches and help try:
>>>>>>>>>> *   http://www.stata.com/help.cgi?search
>>>>>>>>>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>>>>>>>>>> *   http://www.ats.ucla.edu/stat/stata/
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>> *
>>>>>>>> *   For searches and help try:
>>>>>>>> *   http://www.stata.com/help.cgi?search
>>>>>>>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>>>>>>>> *   http://www.ats.ucla.edu/stat/stata/
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Rispetta l'ambiente: se non ti è necessario, non stampare questa mail
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>           Le informazioni contenute in questa comunicazione e gli
>>>>>>> eventuali documenti allegati
>>>>>>>
>>>>>>>           hanno carattere confidenziale e sono a uso esclusivo del
>>>>>>> destinatario. Nel caso
>>>>>>>
>>>>>>>           questa comunicazione Vi sia pervenuta per errore, Vi informo
>>>>>>> che la sua diffusione
>>>>>>>
>>>>>>>           e riproduzione è contraria alla legge e prego di darmi
>>>>>>> prontamente avviso
>>>>>>>
>>>>>>>           e di cancellare quanto ricevuto. Grazie.
>>>>>>>
>>>>>>> *
>>>>>>> *   For searches and help try:
>>>>>>> *   http://www.stata.com/help.cgi?search
>>>>>>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>>>>>>> *   http://www.ats.ucla.edu/stat/stata/
>>>>>>
>>>>>> *
>>>>>> *   For searches and help try:
>>>>>> *   http://www.stata.com/help.cgi?search
>>>>>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>>>>>> *   http://www.ats.ucla.edu/stat/stata/
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Rispetta l'ambiente: se non ti è necessario, non stampare questa mail
>>>>>
>>>>>
>>>>>
>>>>>           Le informazioni contenute in questa comunicazione e gli
>>>>> eventuali documenti allegati
>>>>>
>>>>>           hanno carattere confidenziale e sono a uso esclusivo del
>>>>> destinatario. Nel caso
>>>>>
>>>>>           questa comunicazione Vi sia pervenuta per errore, Vi informo
>>>>> che la sua diffusione
>>>>>
>>>>>           e riproduzione è contraria alla legge e prego di darmi
>>>>> prontamente avviso
>>>>>
>>>>>           e di cancellare quanto ricevuto. Grazie.
>>>>
>>>>
>>>>
>>>> --
>>>> Rispetta l'ambiente: se non ti è necessario, non stampare questa mail
>>>>
>>>>
>>>>
>>>>           Le informazioni contenute in questa comunicazione e gli
>>>> eventuali documenti allegati
>>>>
>>>>           hanno carattere confidenziale e sono a uso esclusivo del
>>>> destinatario. Nel caso
>>>>
>>>>           questa comunicazione Vi sia pervenuta per errore, Vi informo
>>>> che la sua diffusione
>>>>
>>>>           e riproduzione è contraria alla legge e prego di darmi
>>>> prontamente avviso
>>>>
>>>>           e di cancellare quanto ricevuto. Grazie.
>>>>
>>>> *
>>>> *   For searches and help try:
>>>> *   http://www.stata.com/help.cgi?search
>>>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>>>> *   http://www.ats.ucla.edu/stat/stata/
>>>
>>> *
>>> *   For searches and help try:
>>> *   http://www.stata.com/help.cgi?search
>>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>>> *   http://www.ats.ucla.edu/stat/stata/
>>
>>
>>
>> --
>> Rispetta l'ambiente: se non ti è necessario, non stampare questa mail
>>
>>
>>
>>           Le informazioni contenute in questa comunicazione e gli
>> eventuali documenti allegati
>>
>>           hanno carattere confidenziale e sono a uso esclusivo del
>> destinatario. Nel caso
>>
>>           questa comunicazione Vi sia pervenuta per errore, Vi informo
>> che la sua diffusione
>>
>>           e riproduzione è contraria alla legge e prego di darmi
>> prontamente avviso
>>
>>           e di cancellare quanto ricevuto. Grazie.
>>
>> *
>> *   For searches and help try:
>> *   http://www.stata.com/help.cgi?search
>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>> *   http://www.ats.ucla.edu/stat/stata/
>
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/faqs/resources/statalist-faq/
> *   http://www.ats.ucla.edu/stat/stata/



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          Le informazioni contenute in questa comunicazione e gli
eventuali documenti allegati

          hanno carattere confidenziale e sono a uso esclusivo del
destinatario. Nel caso

          questa comunicazione Vi sia pervenuta per errore, Vi informo
che la sua diffusione

          e riproduzione è contraria alla legge e prego di darmi
prontamente avviso

          e di cancellare quanto ricevuto. Grazie.

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/


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