Echoing an older inquiry (https://stat.ethz.ch/pipermail/r-help/2008-November/180184.html), does anyone know of R code that exists to correct for sample selection with panel data as in: J.M. Wooldridge (1995), “Selection Corrections for Panel Data Models Under Conditional Mean Independence Assumptions,” Journal of Econometrics 68, 115-132. Thank you, Jen [[alternative HTML version deleted]]