Treatment and control

[Federica Mezza]

Dear all, I have to create a treatment and a control group. For example, I have a variable called "b" and I have to divide a between treatment and control. On another variable "a" there is written a number 1 and 0. It is on the side of "b" and the meaning is that it assign each observation to treatment and control. How do I divide "b" on the basis of the information contained in "a" ?

[Mike Lacy]

I fear I am misunderstanding your goal, since I'm not familiar with the terminology "on the side of b." However, given what you say, you could use the treatment/control information in "a" to define "b" by simply doing:

replace b = a

If this misses your meaning, I'd suggest you post some example data, using -dataex- as described in the FAQ. For most of us, it's easier to illustrate our goal with data than describe it fully in words.