TY  - BOOK
AU  - Gelman, Andrew
AU  - Imbens, Guido
ED  - National Bureau of Economic Research
TI  - Why ask why?: Forward causal inference and reverse causal questions 
T2  - NBER Working Paper
PY  - 2013///
CY  - Cambridge
PB  - NBER
KW  - NBERWP 19614
KW  - E10767.pdf
UR  - http://elibrary.igidr.ac.in/e-library/working papers/NBER/2013/E10767.pdf
ER  -