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Re: st: example about choice experiment datasheet


From   Arne Risa Hole <arnehole@gmail.com>
To   statalist <statalist@hsphsun2.harvard.edu>
Subject   Re: st: example about choice experiment datasheet
Date   Tue, 27 Nov 2012 11:45:07 +0000

You are welcome. -mixlogit- implements the same model as -asclogit-
but with random coefficients. You should make sure that you understand
the differences between the models before moving on to -mixlogit-, as
this is a more complicated model.

Arne

On 27 November 2012 05:31, elisabetta capobianco
<elisabetta.capobianco@gmail.com> wrote:
> Dear Arne,
> you're my very helpful, thank you so much.
> Now i'm trying to use mix logit, I've ridden your article. It seems to
> be better than asclogit, because i have different alternatives on N
> choices occasion. Is it more correct for my case, isn't it?
>
> Thank you!
>
> elisabetta
>
> 2012/11/26 Arne Risa Hole <arnehole@gmail.com>:
>> This is to be expected; if you found it surprising you need to read
>> the -asclogit- manual entry more carefully. Whether it's correct or
>> not really depends on what you are trying to do. I would suggest that
>> including socio-demographics in your model only makes sense if you
>> interact them with the alternative-specific attributes, since your
>> alternatives are unlabelled.
>>
>> Arne
>>
>> On 26 November 2012 10:43, elisabetta capobianco
>> <elisabetta.capobianco@gmail.com> wrote:
>>> Ok Arne,
>>> now It's clear and I have had good results.
>>> Just a doubt. When I put inside the socio-demographic variables, the
>>> output has the four alternatives 1,2,3,4, even if I write nocons.
>>> I don't understand the meaning of this output considering that I have
>>> unlabelled alternatives.
>>> Is however correct this result?
>>>
>>> Thank you,
>>> Elisabetta
>>>
>>>
>>>
>>>
>>>
>>> 2012/11/24 Arne Risa Hole <arnehole@gmail.com>:
>>>> Elisabetta,
>>>>
>>>> The "case" variable must a unique identifier for each choice. You can
>>>> generate it like this
>>>>
>>>> egen caseid = group(id scenario)
>>>>
>>>> The "alt" variable should be coded 1,2,3,4,1,2,3,4 etc. (not
>>>> 1,2,3,4,5,6,7,8,...).
>>>>
>>>> Arne
>>>>
>>>> On 24 November 2012 16:04, elisabetta capobianco
>>>> <elisabetta.capobianco@gmail.com> wrote:
>>>>> 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
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>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> --
>>>>>>>>>>>> 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/
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> 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.
>
> *
> *   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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