UNDERSTANDING INSTRUMENTAL VARIABLES IN MODELS WITH ESSENTIAL HETEROGENEITY
| Year of publication: |
2006
|
|---|---|
| Authors: | Heckman, James J. ; Urzua, Sergio ; Vytlacil, Edward J. |
| Published in: |
Working paper / National Bureau of Economic Research, Inc. - Cambridge, Mass, ISSN 0898-2937, ZDB-ID 12239057. - 2006, 12574
|