RT Journal Article SR Electronic T1 On the Validity of Econometric Techniques with Weak Instruments JF Journal of Human Resources JO J Hum Resour FD University of Wisconsin Press SP 393 OP 410 DO 10.3368/jhr.XL.2.393 VO XL IS 2 A1 Cruz, Luiz M. A1 Moreira, Marcelo J. YR 2005 UL http://jhr.uwpress.org/content/XL/2/393.abstract AB We evaluate Angrist and Krueger (1991) and Bound, Jaeger, and Baker (1995) by constructing reliable confidence regions around the 2SLS and LIML estimators for returns-to-schooling regardless of the quality of the instruments. The results indicate that the returns-to-schooling were between 8 and 25 percent in 1970 and between 4 and 14 percent in 1980. Although the estimates are less accurate than previously thought, most specifications by Angrist and Krueger (1991) are informative for returns-to-schooling. In particular, concern about the reliability of the model with 178 instruments is unfounded despite the low first-stage F-statistic. Finally, we briefly discuss bias-adjustment of estimators and pretesting procedures as solutions to the weak-instrument problem.