Heckman, James J.; Navarro, Salvador - 2003 - Final draft January, 2003
of selection) in matching, instrumental variable and control functions methods. (2) It contrasts the roles of exclusion … restrictions in matching and selection models. (3) It characterizes the sensivity of matching to the choice of conditioning …. (4) It demonstrates the problem of choosing the conditioning variables in matching and the failure of conventional model …
