Create a Binary Variable that Indicate if a student was Retained in Grades in a Long Format Dataset.

[smith Jason]

I have a small dataset, which is layout in long format.
What I want is to create a new variable "retain" with the rules as follows,
as long as there is a "1" on the state variable within id, then the value of retain should be equal to 1 within id.
if all values of state variable within id =0, then then the value of retain should be equal to 0 within id.
if all values of state variable within id =1, then then the value of retain should be equal to 1 within id.
Can someone help me to do this with Stata code?
Thank you!


clear
input str10 id byte (grade state)
1 1 0
1 2 0
1 3 0
2 1 0
2 1 1
2 2 0
3 1 0
3 2 0
3 2 1
4 1 0
4 2 0
4 2 1
4 3 0
end

[Hemanshu Kumar]

bys id: egen byte retain = max(state)

this assumes that state is binary.

[smith Jason]

bys id: egen byte retain = max(state)

this assumes that state is binary.

Thank you!

[Nick Cox]

For more discussion if needed

https://www.stata.com/support/faqs/d...ble-recording/

[smith Jason]

For more discussion if needed

https://www.stata.com/support/faqs/d...ble-recording/

Thank you for your resources!