CODEWITHSUNDEEP
statisticsstatapanel-data
Stef Lo
Stef Lo

Reputation: 13

How to fill out observations using data from previous years in Stata? (Paneldata)

I have panel data and have missing information on birthyear in some observations. As the birthyear does not differ per ID throughout the time-series I want to fill in the blank spots using a command I do not know of (else I have to do it manually)

Here an example


     +--------------------------------+
     |           ID   wave   birthy~r |
     |--------------------------------|
  1. | 010104101001      1       1965 |
  2. | 010104101001      2       1965 |
  3. | 010104101001      3       1965 |
  4. | 010104101001      4       1965 |
  5. | 010104101002      1       .    |
     |--------------------------------|
  6. | 010104101002      2       .    |
  7. | 010104101002      3       1963 |
  8. | 010104101002      4       1963 |
  9. | 010104102001      1       1954 |
 10. | 010104102001      2       .    |
     +--------------------------------+

In this case I want to automatically replace the missing birthyear values of line 5 and 6 with the information of line 6 or 7. And paste the birthyear value from line 9 into 10.

Upvotes: 0

Views: 965

Answers (1)

Nick Cox
Nick Cox

Reputation: 37358

bysort ID : egen min = min(birthyear) 
by ID: egen max = max(birthyear) 
list if min != max 

bysort ID (birthyear) : replace birthyear = birthyear[1] if max == min

Most of this code is just checking that there isn't contradictory information on birth year (and not overwriting any such).

Upvotes: 1

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