st: betacoef for new variable?

[Fabian Nagel <Fabian.Nagel@uni-konstanz.de>]

Dear Stata-community,

I want to generate a new variable containing the current value of the  
beta-coefficient for each country, each year. The dataset includes 30  
countries for the period from 1980-2003.

My last thought was:

forvalues i=1/30 {
reg conver lag_log_ssegdp if country==`i', noconstant
betacoef
generate beta=r(beta) if country==`i'
}

The problems I have now are:

1.
I want the beta-coefficient to be calculated for each year AND each  
country and not only for each country, but right now I have no idea  
how I can achieve this.

2.
When the loop generates beta=r(beta) I receive the r(109), type  
mismatch. Is there any possibility to save the beta-coefficients (for  
each year and each country) as a new variable?

Thanks for any suggestion in advance,
 Fabian


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