TY  - JOUR
TI  - Avoiding Invalid Instruments and Coping with Weak Instruments
AU  - Michael Peter Murray
JO  - The Journal of Economic Perspectives
PY  - 2006
VL  - 20
IS  - 4
DO  - 10.1257/jep.20.4.111
UR  - https://doi.org/10.1257/jep.20.4.111
ER  -