I have what is likely a simple regression problem.

I am imputing Variable X from survey Y to survey Z. I am using a simple linear regression model and the predict function in STATA.

So, I run a regression on Variable X in survey Y, using a host of independent dummy variables. Then I use the predict command to impute variable X onto survey Z using the regression parameters on the same dummy variables in Z. So far, so good.

However, the original variable in survey Y has 60% of observations equal to zero. But, when I impute none of the observations are zero. This is important as I need a similar proportion of my imputed variable equal to zero.

Does anyone have any idea how I can constrain my imputation to contain a similar proportion of zeros without arbitrarily adding zeros here or there? I've got a feeling that hotdecking might be my answer but would appreciate some further advice.

I'm off on holiday for a few weeks so looking forward to seeing some responses when I get back!

Dom