How can I find what control units are being matched to my treated units in PSMATCH2?

[Kevin Grier]

I am doing matching, but want to estimate the treatment effect via a Dif in Dif instead of just the post-treatment difference between the treated and the matched controls. However, I can't see in PSMATCH2, how to find which observations are being matched to my treated units with nearest neighbor matching. Can anyone help me out?

[William Lisowski]

Welcome to Statalist, Kevin.

The output of help psmatch2 tells us that it adds a number of new variables to the dataset, and among them _id and _n1 (and for k-nearest-neighbor, _n2 through _nk) seem to be what you need to be looking at.

[Kevin Grier]

Thank you William