Drop survey families where parents are not in specific survey rounds

[Cora Touchstone]

Hi all,

I would like to drop any family (as shown by their famid) when the "Head" and "Spouse" do not have data in the years 1984 and 1989. So, I would like to drop all given members with the same famid if there is no data for the Head and Spouse in those years. I would like to keep families when this is not the case. What is an efficient way to do this? I have tried using egen and _N, but am not sure how to specify just the years 1984 and 1989. Below is an example of a family I would like to drop, which includes a Head, Spouse, and three Children.

Thank you!
Cora

Code:

* Example generated by -dataex-. To install: ssc install dataex
clear
input float ID int year float(famid Head Spouse Child)
6004 1985 6 . 1 .
6004 1986 6 . 1 .
6004 1993 6 . 1 .
6030 1985 6 . . 1
6030 1986 6 . . 1
6030 1993 6 . . 1
6031 1985 6 . . 1
6031 1986 6 . . 1
6031 1993 6 . . 1
6170 1985 6 1 . .
6170 1986 6 1 . .
6170 1993 6 1 . .
6171 1985 6 . . 1
6171 1986 6 . . 1
6171 1993 6 . . 1
end

[George Ford]

g keepers = cond(Head==1 & Spouse==1 & (year==1984 | year==1989), 1, 0, .)

And, in the future, when you provide data, make sure the conditions you are interested in are included.

[Clyde Schechter]

Your example data isn't very helpful because nobody in the example has any data at all for 1984 or 1988. I'm also uncertain how you want to handle a situation where a Head or Spouse, but not both, has data in those years. I'll assume you want to exclude them. I believe this works:

by famid, sort: egen has_84_and_88_data = ///
    min(inlist(year, 1984, 1988) & !missing(Head, Spouse))
    
keep if has_84_and_88_data

[Cora Touchstone]

Thank you for the quick response!

I assume I should drop any observations when "keepers" equals 0? The only problem is, keepers is "0" for this family example below (which I would like to keep).

* Example generated by -dataex-. To install: ssc install dataex
clear
input float ID int year float(famid Head Spouse Child keepers)
1959001 1984 1959 1 . . 0
1959001 1985 1959 1 . . 0
1959001 1986 1959 1 . . 0
1959001 1987 1959 1 . . 0
1959001 1988 1959 1 . . 0
1959001 1989 1959 1 . . 0
1959002 1984 1959 . 1 . 0
1959002 1985 1959 . 1 . 0
1959002 1986 1959 . 1 . 0
1959002 1987 1959 . 1 . 0
1959002 1988 1959 . 1 . 0
1959002 1989 1959 . 1 . 0
1959005 1984 1959 . . 1 0
1959005 1985 1959 . . 1 0
1959005 1986 1959 . . 1 0
1959005 1987 1959 . . 1 0
1959005 1988 1959 . . 1 0
1959005 1989 1959 . . 1 0
end

Is there anything else to be done?

Thanks again!
Cora

[Cora Touchstone]

Hi Clyde Schechter,

Thanks for the reply! I can provide an example of both below (I would like to keep famid==1951 and drop famid==6). Additionally, I would like to drop families where a Head or Spouse has data for 1984 and 1989, but not both. Thanks again!

* Example generated by -dataex-. To install: ssc install dataex
clear
input float ID int year float(famid Head Spouse Child)
   6004 1985    6 . 1 .
   6004 1986    6 . 1 .
   6004 1993    6 . 1 .
   6030 1985    6 . . 1
   6030 1986    6 . . 1
   6030 1993    6 . . 1
   6031 1985    6 . . 1
   6031 1986    6 . . 1
   6031 1993    6 . . 1
   6170 1985    6 1 . .
   6170 1986    6 1 . .
   6170 1993    6 1 . .
   6171 1985    6 . . 1
   6171 1986    6 . . 1
   6171 1993    6 . . 1
1959001 1984 1959 1 . .
1959001 1985 1959 1 . .
1959001 1986 1959 1 . .
1959001 1987 1959 1 . .
1959001 1988 1959 1 . .
1959001 1989 1959 1 . .
1959002 1984 1959 . 1 .
1959002 1985 1959 . 1 .
1959002 1986 1959 . 1 .
1959002 1987 1959 . 1 .
1959002 1988 1959 . 1 .
1959002 1989 1959 . 1 .
1959005 1984 1959 . . 1
1959005 1985 1959 . . 1
1959005 1986 1959 . . 1
1959005 1987 1959 . . 1
1959005 1988 1959 . . 1
1959005 1989 1959 . . 1
end

[Clyde Schechter]

First, my response in #3 crossed with #2.

#5 clears up my uncertainty about handling cases where Head or Spouse data, but not both, are present--in the opposite direction of what I had assumed. The following should handle all cases correctly:

by famid, sort: egen byte OK84 = max(cond(year == 1984, !missing(Head) | !missing(Spouse), 0))
by famid: egen byte OK88 = max(cond(year -- 1988, !missing(Head) | !missing(Spouse), 0))
keep if OK84 & OK88

[Cora Touchstone]

Clyde Schechter,

This worked perfectly for me! Many thanks.

Best,
Cora