st: Multiplying variables / Generating new variables after 'mi impute' - STATA 11

[Moses Lee <Moses.Lee@anu.edu.au>]

Hi STATA listers.

I'm wondering if any if you could advise the following.

I need to perform production function regression. This requires 2 stage.

1) Impute missing variables
2) Generate new variables - by multiplying two existing variables after 
imputing missing variables.

I have tried running 'mi impute mvn' command. However, I realised the 
imputed values do not replace the missing values in the original 
variables. This becomes a problem if I need to estimate new variables 
which require a product of the original variables.

An example: X and Y are variables that require imputing. After running 
the mi impute command, I need to 'gen (newvar)=X*Y. However, if the 
missing values in the existing X and Y are not replaced with the imputed 
values, I'm unable to generate a new variable.

Can someone advise on how to replace missing values with imputed values? 
It seems impossible to generate new vars with the estimated imputed values.

Many thanks.
Moses

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