Set data quarterly: Error with quarters (time, "YQ")

[Moritz Weis]

Dear all,

I want to conduct a panel data analysis using a very large dataset with close to 2b observations. I am using Stata 16 for Windows.

My time variable is in string format and and the data looks as follows:

ID	time	price
AB123	2010Q1	10
AB123	2010Q2	11
BG235	2011Q2	500
BG235	2011Q3	550
QWE89	2016Q4	1000

Here, I attempted to use time as a time variable using the following command:

gen time2 =quarter(time, "YQ")
format time2 %tq

However, I always receive the error message:

time, "YQ" invalid name
r(198),

I am not sure where this error comes from as this solution had been successfully implemented in similar previous posts. Hence, I would kindly like to ask you how to circumvent this problem.

Thank you very much for your advice in advance!

Best regards,

[Ali Atia]

quarter() is the function to extract quarters from daily dates. quarterly() is the function to convert quarterly dates stored as strings to Stata Internal Format dates. You should use the latter:

. gen time2 =quarterly(time, "YQ")

. gen time3 =quarter(dofq(time2))

. format time2 %tq

. list time*

     +-------------------------+
     |   time    time2   time3 |
     |-------------------------|
  1. | 2010Q1   2010q1       1 |
  2. | 2010Q2   2010q2       2 |
  3. | 2011Q2   2011q2       2 |
  4. | 2011Q3   2011q3       3 |
  5. | 2016Q4   2016q4       4 |
     +-------------------------+

[Moritz Weis]

Wonderful! Thank you very much, I must have overlooked the ending so far. It worked out perfectly.