Dear community, I want to estimate LA-AIDS with homogeneity and symmetry conditions imposed. I have four commodities: beef, pork, chicken, turkey.

First I run a command without restrictions which work out just fine:

*without constraints imposed:

global demand1 "(q1: expsharebeef lnrpbeef lnrppork lnrpchicken lnrpturkey ln_m_p)"
global demand2 "(q2: expsharepork lnrpbeef lnrppork lnrpchicken lnrpturkey ln_m_p)"
global demand3 "(q3: expsharechicken lnrpbeef lnrppork lnrpchicken lnrpturkey ln_m_p)"
global demand4 "(q3: expshareturkey lnrpbeef lnrppork lnrpchicken lnrpturkey ln_m_p)"
sureg $demand1 $demand2 $demand3

Then I define constraints and then run sureg with constraints:

*with constraints:


*constraint: symmetry
constraint define 1 [disappearancebeefcanada]lnrppork= [disappearanceporkcanada]lnrpbeef
constraint define 2 [disappearancebeefcanada]lnrpchicken= [disappearancechickencanada]lnrpbeef
constraint define 3 [disappearancebeefcanada]lnrpturkey=[disappearanceturkeycanada]lnrpbeef
constraint define 4 [disappearanceporkcanada]lnrpchicken= [disappearancechickencanada]lnrppork
constraint define 5 [disappearanceporkcanada]lnrpturkey=[disappearanceturkeycanada]lnrppork
constraint define 6 [disappearancechickencanada]lnrpturkey=[disappearanceturkeycanada]lnrpchicken

*constraint homogeneity
constraint define 7 [disappearancebeefcanada]lnrpbeef+[disappearancebeefcanada]lnrppork+[disappearancebeefcanada]lnrpchicken+[disappearancebeefcanada]lnrpturkey=0

constraint define 8 [disappearancechickencanada]lnrpbeef+[disappearancechickencanada]lnrppork+[disappearancechickencanada]lnrpchicken+[disappearancechickencanada]lnrpturkey=0
constraint define 9 [disappearanceporkcanada]lnrpbeef+[disappearanceporkcanada]lnrppork+[disappearanceporkcanada]lnrpchicken+[disappearanceporkcanada]lnrpturkey=0
constraint define 10 [disappearanceturkeycanada]lnrpbeef+[disappearanceturkeycanada]lnrppork+[disappearanceturkeycanada]lnrpchicken+[disappearanceturkeycanada]lnrpturkey=0

*run sureg
sureg $demand1 $demand2 $demand3, const(1 2 3 4 5 6 7 8 9 10) isure

The stata output provides me the same result as of before but it also says:

(note: constraint number 1 caused error r(303))
(note: constraint number 2 caused error r(303))
(note: constraint number 3 caused error r(303))
(note: constraint number 4 caused error r(303))
(note: constraint number 5 caused error r(303))
(note: constraint number 6 caused error r(303))
(note: constraint number 7 caused error r(303))
(note: constraint number 8 caused error r(303))
(note: constraint number 9 caused error r(303))
(note: constraint number 10 caused error r(303))
(note: constraint number 1 caused error r(303))
(note: constraint number 2 caused error r(303))
(note: constraint number 3 caused error r(303))
(note: constraint number 4 caused error r(303))
(note: constraint number 5 caused error r(303))
(note: constraint number 6 caused error r(303))
(note: constraint number 7 caused error r(303))
(note: constraint number 8 caused error r(303))
(note: constraint number 9 caused error r(303))
(note: constraint number 10 caused error r(303))


Thinking that this is causing because I need to drop one share equation and their associated commands, I dropped constraint related to turkey and run again. It is still saying the above error. That constraint no 1... caused error. What should I do? How can I solve this, please?