Estimating WTP after biprobit

[Rezgar Mostafa]

Hello. I have a problem estimating the WTP after running the biprobit model. Any help would be highly appreciated.

[Carlo Lazzaro]

Rezgar:
welcome to this forum.
As per FAQ, please post what you typed and what Stata gave you back. Thanks.

[Rezgar Mostafa]

Dear Dr. Carlo Lazzaro,

Thank you for the clarification. This is my model:
biprobit bid1 bid2 perception knowledge age income
where
bid1=1 if the response to the first question is yes, and 0 otherwise
bid2=1 if the response to the second question is yes, and 0 otherwise
perception, knowledge, and income are categorical variables
age is a continuous variable

when I try to run this model:
wtpcikr perception knowledge age income, equation(bid1)
I receive this message:
factor-variable and time-series operators not allowed

Thank you for your assistance.

[Carlo Lazzaro]

Rezgar:
what if you type:

xi: wtpcikr perception knowledge age income, equation(bid1)

[Rezgar Mostafa]

Dear Dr. Lazzaro,

It worked. I greatly appreciate your help.

Best regards,
Rezgar