[Limdep Nlogit List] Error message in running Stated Choice Model
Puri,Mahi
mpuri at ufl.edu
Sun Mar 29 10:19:30 AEDT 2020
Hello
I am using NLOGIT (version 6) and trying to run Mixed (Random Parameter) Logit Model for stated choice experiment data. However, the model is giving an error and we are unable to proceed. Please advice.
The code, description of data and error message are provided below:
1.
The data is in the form of panel data (3 repetitions) where each respondent is given 3 choices (alt 1, alt 2, none). So, 600 respondents*3 choices*3 repetitions = 5400 rows of data
2.
The attributes (land, year, payment) vary over choices.
3.
Covariates/characteristics (padist, fcov, herbcon, inputs, benefits, respage, respedu, hhmem, #caste, history, landsize, aginc, crops, otherinc, sources) vary across respondents.
4.
"land" and "year" are random parameters
|-> NLOGIT; Lhs = choiced
; Choices = alt1, alt2, none
; model:
U(alt1) = b_land * land + b_year * year + b_payment * payment/
U(alt2) = b_land * land + b_year * year + b_payment * payment/
U(none) = asc + b_land * land + b_year * year + b_payment * payment
; RPL = padist, fcov, herbcon, inputs, benefits, respage, respedu, hhmem, #caste, history, landsize, aginc, crops, otherinc, sources
; Pts = 500; Halton; Pds = 3
; Fcn = b_land(n), b_year(n)$
-----------------------------------------------------------------------------
Start values obtained using MNL model
Dependent variable Choice
Log likelihood function -1588.38429
Estimation based on N = 1773, K = 4
Inf.Cr.AIC = 3184.8 AIC/N = 1.796
---------------------------------------
Log likelihood R-sqrd R2Adj
Constants only -1913.0514 .1697 .1602
Note: R-sqrd = 1 - logL/Logl(constants)
Warning: Model does not contain a full
set of ASCs. R-sqrd is problematic. Use
model setup with ;RHS=one to get LogL0.
---------------------------------------
Response data are given as ind. choices
Number of obs.= 1800, skipped 27 obs
--------+--------------------------------------------------------------------
| Standard Prob. 95% Confidence
CHOICED| Coefficient Error z |z|>Z* Interval
--------+--------------------------------------------------------------------
B_LAND| -.04070*** .00181 -22.51 .0000 -.04425 -.03716
B_YEAR| -.02464** .01144 -2.15 .0313 -.04707 -.00221
B_PAYMEN| .01460*** .00225 6.50 .0000 .01020 .01900
ASC| -1.59020*** .16806 -9.46 .0000 -1.91960 -1.26080
--------+--------------------------------------------------------------------
***, **, * ==> Significance at 1%, 5%, 10% level.
Model was estimated on Mar 28, 2020 at 06:25:54 PM
-----------------------------------------------------------------------------
Error 805: Initial iterations cannot improve function.Status=3
Function value was .1588384288D+04 at entry -----------
.3124865903D+05 at exit -----------
Error 1025: Failed to fit model. See earlier diagnostic.
----
Mahi Puri
PhD Candidate and Graduate Assistant
Wildlife Ecology and Conservation
University of Florida
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