[Limdep Nlogit List] Interaction between ASC and socio-economic variables

[Fredrik Carlsson]

You can’t interact with an ASC in U(1,2) since you don’t have an ASC there then.

F

From: F WD [mailto:fannywidadie at gmail.com]
Sent: Thursday, 18 June 2020 09:26
To: Fredrik Carlsson <fredrik.carlsson at economics.gu.se>
Cc: Limdep and Nlogit Mailing List <limdep at mailman.sydney.edu.au>
Subject: Re: [Limdep Nlogit List] Interaction between ASC and socio-economic variables

Dear Fredik Carlsson,

Actually, I don't use ASC in the second utility function in my model. I made a mistake to write the syntax in the previous mail. I use the syntax as below:

RPLOGIT   ; Lhs = CHOICE ; Choices = 1,2,3
;model:
U(1,2) = PRICE*PRICE + X76*X76 + HANDLING*HANDLING + X62*X62 + X63*X63 + LOCATION*LOCATION + X65*X65 + QUANTITY*QUANTITY +
AGE*ASCXAGE + EDUC*ASCXEDUC + ORGANIC*ASCXORGA + RISK*X104 + KTPA*ASCXKTPA + COMMUNITY*ASCXKTCO + INCOME*ASCXINCO /
U (3) =  ASC + PRICE*PRICE + X76*X76 + HANDLING*HANDLING + X62*X62 + X63*X63 + LOCATION*LOCATION + X65*X65 + QUANTITY*QUANTITY
; fcn = ASC(n), Price(c), X76(n), HANDLING(n), X62(n), X63(n), LOCATION(n), X65(n), QUANTITY(n)
; Maxit = 50 ; Pts = 25 ; Halton ; Output = 3 ; Pds = 3 $

when I run the result is Error   1027: Models - estimated variance matrix of estimates is singular..


Pada tanggal Kam, 18 Jun 2020 pukul 00.40 Fredrik Carlsson <fredrik.carlsson at economics.gu.se<mailto:fredrik.carlsson at economics.gu.se>> menulis:
You have an ASC in all utility fcns in the second specification

Best
Fredrik

Skickat från min iPhone

> 17 juni 2020 kl. 16:51 skrev F WD via Limdep <limdep at mailman.sydney.edu.au<mailto:limdep at mailman.sydney.edu.au>>:
>
> Dear all,
>
> I am using a mixed logit model to estimate the preferences. In my model,
> there are two types of alternatives and a status quo (alternative specific
> constants). So basically, I had three utility functions. When I tried to
> estimate the basic model without interaction with some socio-economic
> variables, it works. However, When I tried to add the model with
> interaction between ASC and socio-economic variables, it did not work. As
> for your information, I use ASC to measure utility of status quo
> alternative. I use dummy variable coding 1 if the respondent chooses the
> status quo, and 0 otherwise. I want to know the effect of socio-economic
> variable on the probability to opt “status quo”.
>
> The syntax of mixed logit is below for basic model and it run well
>
> RPLOGIT   ; Lhs = CHOICE ; Choices = 1,2,3
>
> ;model:
>
> U(1,2) = PRICE*PRICE + X76*X76 + HANDLING*HANDLING + X62*X62 + X63*X63      +
> LOCATION*LOCATION + X65*X65  +  QUANTITY*QUANTITY /
>
> U (3) =  ASC + PRICE*PRICE + X76*X76 + HANDLING*HANDLING + X62*X62 +
> X63*X63 + LOCATION*LOCATION + X65*X65 + QUANTITY*QUANTITY
>
> ; fcn = ASC(n), Price(c), X76(n), HANDLING(n), X62(n), X63(n), LOCATION(n),
> X65(n), QUANTITY(n)
>
> ; Maxit = 50 ; Pts = 25 ; Halton ; Output = 3 ; Pds = 3 $
>
>
>
> However, when I run to interact between ASC and some socio-economic
> variables, it does not work.  I got the message: *Error   1027: Models -
> estimated variance matrix of estimates is singular*
>
> I use the syntax below:
>
> RPLOGIT   ; Lhs = CHOICE ; Choices = 1,2,3
>
> ;model:
>
> U(1,2) = ASC + PRICE*PRICE + X76*X76 + HANDLING*HANDLING + X62*X62 +
> X63*X63 + LOCATION*LOCATION + X65*X65 + QUANTITY*QUANTITY +  AGE*ASCXAGE +
> EDUC*ASCXEDUC + ORGANIC*ASCXORGA + RISKst*ASCXRISK + KTPA*ASCXKTPA +
> COMMUNITY*ASCXKTCO /
>
> U (3) = ASC + PRICE*PRICE + X76*X76 + HANDLING*HANDLING + X62*X62 + X63*X63
> + LOCATION*LOCATION + X65*X65 + QUANTITY*QUANTITY
>
> ; fcn = ASC(n), Price(c), X76(n), HANDLING(n), X62(n), X63(n), LOCATION(n),
> X65(n), QUANTITY(n),
>
> ; Maxit = 50 ; Pts = 25 ; Halton ; Output = 3 ; Pds = 3 $
>
>
>
> Does anyone know why the model in the interaction is not run? Is there any
> wrong in the syntax? Thank you for your help.
>
> best regards,
> F
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--

Fanny Widadie, S.P., M.Agr
Department of Agricultural Economics and Agribusiness
Faculty of Agriculture
University of Sebelas Maret
Jalan Ir. Sutami No. 36 A Kentingan Surakarta - Central Java
Indonesia 57126