Production Function Estimation with levpet repeated time values error

[Anton Hantel]

Dear All,

I am trying to estimate a production function using the approach from Levinsohn & Petrin. For this, I installed levpet (st0060).

Now, when I am trying to estimate the production function, I am receiving the "repeated time values within panel r(451)"-error. Interestingly, I am not receiving this error when I am using fixed or random effects regressions.

Additionally, I checked for duplicates with "duplicates list id year", where stata returned that 0 observations were duplicates.

Do you have any ideas what the problem could be?
This is the code I used:

tsset id year
levpet lnrev, free(lnfte) proxy(lnmat) capital(lnkap) revenue

Many thanks,
Anton

[Anton Hantel]

Dear All,

Just in case anyone is having the same problem in the future, it seems as if my id had too many digits and I was able to solve it as follows:

egen newid = group(id)
tsset newid year
levpet lnrev, free(lnfte) proxy(lnmat) capital(lnkap) revenue

Best,
Anton