Conditional summation notation

Post date: 2020-08-01 11:00:48

I'm trying to show a summation for observations i to n, starting with i = 1, that is only applied when another variable (treatment) is equal to 0. What's the correct notation for that?

The idea that I'm trying to turn into mathematical notation is "Each control unit in a given stratum has an uncorrected weight equal to (the unit's survey weight divided by the sum of all survey weights of control units in that stratum) multiplied by (the sum of all survey weights of treatment units in that stratum)," if that helps for context. I feel very self-conscious asking this question; please be kind.

Please click Here to read the full story.