[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]
st: IV Regression with many zeros in 1st stage
Dear Statalist colleagues,
I would like to estimate the following regression:
where BD=birth defect and S is a measure of smoking (either 0/1 or number of
cigarettes). I would like to instrument S with cigarette prices and other
smoking policy variables, eg). The problem, I think, is that > 50% of
smoke. Does affect the appropriateness of the IV approach? Ie, can my 1st
S = cZ+dP+e
be estimated if >50% of S is zero?
Any help would be greatly appreciated.
Michael Ganz, MS, PhD
Dept. of Society, Human Development and Health
Harvard School of Public Health
* For searches and help try: