[Jorge Eduardo Perez Perez]

This is a frequent thread in Statalist, people having trouble with their qaids evaluators. The way to find errors is to use the trace command with a high depth

set trace on
set tracedepth 4

and look at a run of the routine. Look at line 26 of your code:

scalar `g14' = - `g11' - `g12' - `q13'

Thats a q, not a g in q13. Should be

scalar `g14' = - `g11' - `g12' - `g13'

After that, it should work. The following example worked for me:

clear
webuse food

foreach x in dmem location poverty pdf1 pdf2 pdf3 cdf1 cdf2 cdf3 {
    gen `x'=uniform()
}


cap program drop nlsurqaids
program nlsurqaids
version 13
syntax varlist(min=17 max=17) if, at(name) 
tokenize `varlist'
args w1 w2 w3 lnprice1 lnprice2 lnprice3 lnprice4 lnexptot dmem location poverty pdf1 pdf2 pdf3 cdf1 cdf2 cdf3 
// With four goods, parameters can be // estimated, after eliminating one of the goods and // imposing adding up, symmetry, and homogeneity // constraints, in the QUAIDS model // Here, we extract those parameters from the `at'vector, and impose constraints as we go along
///Here, since after incorporating cdf and pdf the right hand side will not add up to one, coefficients of all equations are obtained///
tempname a1 a2 a3 a4 
scalar `a1' = `at'[1,1] 
scalar `a2' = `at'[1,2] 
scalar `a3' = `at'[1,3] 
scalar `a4' = 1 - `a1' - `a2' - `a3'
tempname b1 b2 b3 b4
scalar `b1' = `at'[1,4]
scalar `b2' = `at'[1,5]
scalar `b3' = `at'[1,6]
scalar `b4' = - `b1' - `b2' - `b3'
tempname g11 g12 g13 g14
tempname g21 g22 g23 g24
tempname g31 g32 g33 g34
tempname g41 g42 g43 g44
scalar `g11' = `at'[1,7]
scalar `g12' = `at'[1,8]
scalar `g13' = `at'[1,9]
scalar `g14' = - `g11' - `g12' - `q13'
scalar `g21' = `g12'
scalar `g22' = `at'[1,10]
scalar `g23' = `at'[1,11]
scalar `g24' = - `g21' - `g22' - `g23'
scalar `g31' = `g13'
scalar `g32' = `g23'
scalar `g33' = `at'[1,12]
scalar `g34' = - `g31' - `g32' -`g33'
scalar `g41' = `g14'
scalar `g42' = `g24'
scalar `g43' = `g34'
scalar `g44' = - `g41' - `g42' - `g43'
tempname L1 L2 L3 L4
scalar `L1' = `at'[1,13]
scalar `L2' = `at'[1,14]
scalar `L3' = `at'[1,15]
scalar `L4' = - `L1' - `L2' - `L3'
// constant and household demographics
tempname r12 r13 r14 
tempname r22 r23 r24
tempname r32 r33 r34
tempname r42 r43 r44
scalar `r12' = `at'[1,16]
scalar `r13' = `at'[1,17]
scalar `r14' = `at'[1,18]
scalar `r22' = `at'[1,19]
scalar `r23' = `at'[1,20]
scalar `r24' = `at'[1,21]
scalar `r32' = `at'[1,22]
scalar `r33' = `at'[1,23]
scalar `r34' = `at'[1,24]
scalar `r42' = `at'[1,25]
scalar `r43' = `at'[1,26]
scalar `r44' = `at'[1,27]
// pdf
tempname d1 d2 d3 d4
scalar `d1' = `at'[1,28]
scalar `d2' = `at'[1,29]
scalar `d3' = `at'[1,30]
scalar `d4' = `at'[1,31]
//// Okay, now that we have all the parameters, we can // calculate the expenditure shares.
// Okay, now that we have all the parameters, we can // calculate the expenditure shares.
quietly {
tempvar lnpindex
gen double `lnpindex' = 4 + `a1'*`lnprice1' + `a2'*`lnprice2' + `a3'*`lnprice3' + `a4'*`lnprice4'
forvalues i = 1/4 {
forvalues j = 1/4 {
replace `lnpindex' = `lnpindex' + 0.5*`g`i'`j''*`lnprice`i''*`lnprice`j'' 
}
}
// The b(p) term in the QUAIDS model:
tempvar bofp
gen double `bofp' = 0
forvalues i = 1/4 {
replace `bofp' = `bofp' + `lnprice`i''*`b`i''
}
replace `bofp' = exp(`bofp')


replace `w1' = (`a1' + `g11'*`lnprice1' + `g12'*`lnprice2' + `g13'*`lnprice3' + `g14'*`lnprice4' + `b1'*(`lnexptot' - `lnpindex') + `L1'/`bofp'*(`lnexptot' - `lnpindex')^2 + `r12'*`dmem' + `r13'*`location' + `r14'*`poverty')*`cdf1' + `d1'*`pdf1' 

replace `w2' = (`a2' + `g21'*`lnprice1' + `g22'*`lnprice2' + `g23'*`lnprice3' + `g24'*`lnprice4' + `b2'*(`lnexptot' - `lnpindex') + `L2'/`bofp'*(`lnexptot' - `lnpindex')^2 + `r22'*`dmem' + `r23'*`location' + `r24'*`poverty')*`cdf2' + `d2'*`pdf2' 

replace `w3' = (`a3' + `g31'*`lnprice1' + `g32'*`lnprice2' + `g33'*`lnprice3' + `g34'*`lnprice4' + `b3'*(`lnexptot' - `lnpindex') + `L3'/`bofp'*(`lnexptot' - `lnpindex')^2 + `r32'*`dmem' + `r33'*`location' + `r34'*`poverty')*`cdf3' + `d3'*`pdf3' 


} 
end

nlsur qaids @ w1 w2 w3 lnp1 lnp2 lnp3 lnp4 lnexp dmem location poverty pdf1 pdf2 pdf3 cdf1 cdf2 cdf3, parameters(a1 a2 a3 b1 b2 b3 g11 g12 g13 g14 g22 g23 g24 g33 g34 L1 L2 L3 r12 r13 r14 r22 r23 r24 r32 r33 r34 d1 d2 d3) ifgnls nequations(3)

[Kin Gutierrez]

Dear STATA users

I am trying to estimate an AIDS model for 4 commodities in a panel data base, so far I have used succesfully the Brian Poi's package, I would like to know if there is a way to use only the within household variation.

I would like to know if there is a special treatment for panel data AIDS.

[Srabashi Ray]

Hi everyone ... I posted my question on a different thread before I came upon this thread. I am trying to estimate a system of 4 goods censored demand system using some of the codes that has been shared on these (this and the one linked below) threads. My question on the post (link provided below) refers to the way w1,w2,... is defined which does not seem to match the way Poi (2012) suggests to define it when including demographic variables.

https://www.statalist.org/forums/for...-command/page3

I am also new to Statalist! Hearing back from someone would be awesome!!

Regards,
Srabashi