Hi there! I'd like to learn more about the Heckman selection model to control for selection bias. Here's the situation with our data. We have a large panel data set that is gathered through surveys each year. Organizations can opt to take the survey or not, so the sample doesn't include the entire population of organizations. And then after data cleaning, the sample gets reduced significantly furthering the selection bias. I'm trying to figure out if the Heckman selection model would be the proper technique to control for selection bias in this situation. If so, how do you apply the Heckman model to panel data with fixed effects in Stata?