TY  - JOUR
TI  - Unobservable Selection and Coefficient Stability: Theory and Evidence
AU  - Emily F. Oster
JO  - Journal of Business and Economic Statistics
PY  - 2016
VL  - 37
IS  - 2
DO  - 10.1080/07350015.2016.1227711
UR  - https://doi.org/10.1080/07350015.2016.1227711
ER  -