How to create birth order variable?

[Huda Jabbar]

I am trying to create a birth order variable with the categories of oldest, middle, and youngest. In my data I have a variable that asks how many children do your parents have (answers range 1-16), and another question that asks which order are you within those children (1st-16th). I know for the oldest it would be all those who said they are the first born, but how would you suggest I go about coding the middle and youngest categories?

[George Ford]

This might help get you started.

Say the order variable is "order" and there's a household_id.

clear
input byte(household_id order)
1 1
2 1
2 2
3 1
3 2
3 3
4 1
4 2
4 3
4 4
5 1
5 2
5 3
5 4
5 5
6 1
6 2
6 3
6 4
6 5
6 6
7 1
7 2
7 3
7 4
7 5
7 6
7 7
8 1
8 2
8 3
8 4
8 5
8 6
8 7
8 8
9 1
9 2
9 3
9 4
9 5
9 6
9 7
9 8
9 9
10 1
10 2
10 3
10 4
10 5
10 6
10 7
10 8
10 9
10 10
end

egen kidcount = count(order), by(household_id)

egen order_last = max(order), by(household_id)
egen order_med = median(order), by(household_id)

g firstborn = order == 1
g lastborn  = order == order_last
g medborn = order == int(order_med) if kidcount>2

The issue is the middle born, since with even numbers, you have a tie. You could have 2 middle born in these cases, adding a medborn2 variable with int(order_med)+1

[Huda Jabbar]

This might help get you started.

Say the order variable is "order" and there's a household_id.

clear
input byte(household_id order)
1 1
2 1
2 2
3 1
3 2
3 3
4 1
4 2
4 3
4 4
5 1
5 2
5 3
5 4
5 5
6 1
6 2
6 3
6 4
6 5
6 6
7 1
7 2
7 3
7 4
7 5
7 6
7 7
8 1
8 2
8 3
8 4
8 5
8 6
8 7
8 8
9 1
9 2
9 3
9 4
9 5
9 6
9 7
9 8
9 9
10 1
10 2
10 3
10 4
10 5
10 6
10 7
10 8
10 9
10 10
end

egen kidcount = count(order), by(household_id)

egen order_last = max(order), by(household_id)
egen order_med = median(order), by(household_id)

g firstborn = order == 1
g lastborn = order == order_last
g medborn = order == int(order_med) if kidcount>2

The issue is the middle born, since with even numbers, you have a tie. You could have 2 middle born in these cases, adding a medborn2 variable with int(order_med)+1

Unfortunately I do not have a household_id variable, just the two variables listed and the person's id.

[George Ford]

clear all
set obs 100

g kidshave = int(runiform(0,17))
g myrank = int(runiform(1,15))

g first = myrank==1
g last = myrank==kidshave
g mid = myrank==int(kidshave/2)

[Hemanshu Kumar]

I think the code in #4 works well, except for the mid variable. You could create that using this code instead:

g mid = !first & !last

As an aside, you might get a more sensible toy dataset with this:

clear all
set obs 100

g kidshave = runiformint(1, 17)
g myrank = runiformint(1, kidshave)