st: compare propensity to consume

["Khieu, Hinh" <Hdkhieu@usi.edu>]

Dear statalist members,

I want to compare the propensity to consume 2 products, A and B. across two groups of users. I came up with this model.

Y = (0,1), where 0 if change in Y from t to t+1 increases or equals zero, and 1 if change in Y decreases.

Then, run probit of:

Group1: [Poor group]

 Y = f(product A, product B, other control variables)

Group2: [Rich group]

Y = f(product A, product B, other control variables). The model is exactly the same as group1.

What I want to compare:

Is the probability of A being consumed greater than that of B within Group 1?
Is the probability of A being consumed greater than that of B within Group 2?

Is the probability of A being consumed greater than that of A between Groups 1 and 2?
Is the probability of B being consumed greater than that of B between Groups 1 and 2?

Is the probability of A being consumed greater than that of B between Groups 1 and 2?

My questions:
Does my probit setup above allow me to answer the five questions above.
Does someone have a better suggestion for the specification to more easily answer the five questions of interest?
Is there a built-in Stata function to run AND compare the regression coefficients for groups 1 and 2? I don't know any code to run this regression.

I would appreciate any amount of help. Many thanks in advance.

Regards,
Hinh

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