Examples for modeling selection effect, non-response?

[bgoodri]

If you search on Discourse for Heckman, there are some good threads, such as this one:

Heckman selection model code + simulation

Here’s a Stan program that implements the Heckman likelihood and fits the program to fake data. It recovers the parameters well. I haven’t yet fitted it to repeated simulated datasets though. EDIT: The code below has an error in the likelihood, which @RachaelMeager caught in her post below (link). Follow the link for the explanation, the correct code, and an extension! The likelihood contribution for observed units below should be: log(Phi(sqrt(1 - rho^2)^(-1)*(mu_y2[n_pos[n]] …