entry year is the year which the firm was founded and its among 1986 and 2009. So these values are repeated over the sample.
My first step was joining the economic variables to the base data, my merging it. The problem here is that Gdp values are repeated because entry years are also repeated.
When i try to declare the dataset to be panel data (xtset firmid year) i get the result "repeated time values within panel". I also tried to make a regression but stata says that there's no observations.