TY  - RPRT
        AU  - Heckman, James J.
AU  - Urzua, Sergio
        TI  - Comparing IV with Structural Models: What Simple IV Can and Cannot Identify
        PY  - 2009/Jan/
        PB  - Institute of Labor Economics (IZA)
        CY  - Bonn
        T2  - IZA Discussion Paper
        IS  - 3980
        UR  - https://www.iza.org/publications/dp3980
        AB  - This paper compares the economic questions addressed by instrumental variables estimators with those addressed by structural approaches. We discuss Marschak's Maxim: estimators should be selected on the basis of their ability to answer well-posed economic problems with minimal assumptions. A key identifying assumption that allows structural methods to be more informative than IV can be tested with data and does not have to be imposed.
        KW  - Marschak's Maxim
KW  - instrumental variables
KW  - structural approaches
        ER  -