TY  - JOUR
A1  - Angrist, J.D.
A1  - Krueger, A.B.
T1  - Instrumental variables and the search for identification: from supply and demand to natural experiments
Y1  - 2001
DO  - 10.2139/ssrn.281433
JF  - Journal of Economic Perspectives
VL  - 15
IS  - 4
SP  - 69
EP  - -85

ER  -