TY  - JOUR
T1  - Levels of Measurement and Political Research: An Optimistic View
AU  - Jacoby, William G.
PY  - 1999
SP  - 271
EP  - 301
JO  - American Journal of Political Science
VL  - 43
IS  - 1
SN  - 0092-5853
UR  - http://www.jstor.org/stable/2991794
ER  -