forval k = 10/20 {
egen price`k' = mean(price / (product == `k')), by(time)
}
Nick
n.j.cox@durham.ac.uk
Jorge Alé Chilet
I am working with a panel data. The relevant variables are date, product number and price. I want to create new variables, say, price of products number 10 to 20. For every day, this variable would have the same value across all products.
A way of doing this would be:
forvalues k = 10/20 {
forvalues time = 2392/2547 {
sum price if mydate==`time' & product==`k', meanonly
quietly replace price`k'=r(mean) if mydate==`time'
}
}
The problem is that this takes a long time (huge dataset, many products). Can you think of a faster way of doing this? A possible solution would be to run the loop for every day, but this would imply doing something like this,
by mydate: forvalues k = 10/20 {
sum price if product==`k', meanonly
replace price`k'=r(mean)
}
which is forbidden since forvalues cannot be combined with by.
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