Lee, Soohyung; Shaikh, Azeem M. - In: Journal of Applied Econometrics 29 (2014) 4, pp. 612-626
SUMMARY The effect of a program or treatment may vary according to observed characteristics. In such a setting, it may not only be of interest to determine whether the program or treatment has an effect on some sub‐population defined by these observed characteristics, but also to determine for...