As a medical statistician with no previous knowledge of econom(etr)ics, I struggled to get to grips with instrumental variables as I often struggled to follow their examples and didn't understand their rather different terminology (e.g. 'endogeneity', 'reduced form', 'structural equation', 'omitted variables'). Here's a few references I found useful (the first should be freely available, but I'm afraid the others probably require a subscription):
Staiger D. Instrumental Variables. AcademyHealth Cyber Seminar in Health Services Research Methods, March 2002. http://www.dartmouth.edu/~dstaiger/wpapers-Econ.htm [archived link]
Newhouse JP, McClellan M. Econometrics in Outcomes Research: The Use of Instrumental Variables. Annual Review of Public Health 1998;19:17-34. http://dx.doi.org/10.1146/annurev.publhealth.19.1.17
Greenland S. An introduction to instrumental variables for epidemiologists. International Journal of Epidemiology 2000;29:722-729. http://dx.doi.org/10.1093/ije/29.4.722
Zohoori N, Savitz DA. Econometric approaches to epidemiologic data: Relating endogeneity and unobserved heterogeneity to confounding. Annals of Epidemiology 1997;7:251-257. http://dx.doi.org/10.1016/S1047-2797(97)00023-9
I'd also recommend chapter 4 of:
- Angrist JD, Pischke JS. Mostly harmless econometrics: an empiricist's companion. Princeton, N.J: Princeton University Press, 2009. http://www.mostlyharmlesseconometrics.com/
