Creating time to treat period for event study analysis part 2

[Jenna Kerry]

Hello,

I am having an issue with my data. I have created a simple example data set here:

* Example generated by -dataex-. For more info, type help dataex
clear
input float(Family_id Year had_new_kid Wanted)
1 2000    . 2001
2 2000    .    .
3 2000    .    .
4 2000 2000 2000
5 2000    . 2002
1 2001 2001 2001
2 2001    .    .
3 2001    .    .
4 2001    . 2000
5 2001    . 2002
1 2002    . 2001
2 2002    .    .
3 2002    .    .
4 2002    . 2000
5 2002 2002 2002
1 2003    . 2001
2 2003    .    .
3 2003    .    .
4 2003 2003 2000
5 2003    . 2002
end

Here, I have a panel data set on five families from years 2000 to 2002. Now, I have the year when they have their first kid. Now, I want to run an event study analysis, where I have to create leads and lags period for the families after and from having the first kid. Therefore, I need to create time to treat variables. I got that variable listed as "wanted" here using the following code:

bys Family_id (had_new_kid): gen wanted= had_new_kid[1]

I am having another problem here! Please have a look at the data set above; notice that family_id 4 had kid again at year 2003. Can the previous code still generate the year when they have their first kid? which would still be 2000. In this case I tried the code mentioned above, it worked! However, I still need to determine the families like 4 here, which had kids more than once.

Thank you so much!

[Andrew Musau]

Here is how you can tag such families. I also show how to generate a count of how many times a family had a kid or kids. Note that you cannot use this variable to represent the number of kids because a birth can involve twins, triplets and so on.

isid Family_id Year
bys Family_id: egen frequency= total(!missing(had_new_kid)) 
by Family_id: gen two_or_more= freq>1

Res.:

. l, sepby(Fam)

     +-----------------------------------------------------------+
     | Family~d   Year   had_ne~d   Wanted   freque~y   two_or~e |
     |-----------------------------------------------------------|
  1. |        1   2002          .     2001          1          0 |
  2. |        1   2001       2001     2001          1          0 |
  3. |        1   2003          .     2001          1          0 |
  4. |        1   2000          .     2001          1          0 |
     |-----------------------------------------------------------|
  5. |        2   2000          .        .          0          0 |
  6. |        2   2003          .        .          0          0 |
  7. |        2   2001          .        .          0          0 |
  8. |        2   2002          .        .          0          0 |
     |-----------------------------------------------------------|
  9. |        3   2003          .        .          0          0 |
 10. |        3   2001          .        .          0          0 |
 11. |        3   2000          .        .          0          0 |
 12. |        3   2002          .        .          0          0 |
     |-----------------------------------------------------------|
 13. |        4   2003       2003     2000          2          1 |
 14. |        4   2001          .     2000          2          1 |
 15. |        4   2000       2000     2000          2          1 |
 16. |        4   2002          .     2000          2          1 |
     |-----------------------------------------------------------|
 17. |        5   2002       2002     2002          1          0 |
 18. |        5   2000          .     2002          1          0 |
 19. |        5   2001          .     2002          1          0 |
 20. |        5   2003          .     2002          1          0 |
     +-----------------------------------------------------------+

[Jenna Kerry]

Thanks a lot, Andrew Musau!!