TY  - JOUR
AU  - Aakvik,Arild
AU  - Heckman,James J.
AU  - Vytlacil,Edward J.
TI  - Treatment Effects for Discrete Outcomes when Responses to Treatment Vary Among Observationally Identical Persons: An Application to Norwegian ...
JF  - National Bureau of Economic Research Technical Working Paper Series
VL  - No. 262
PY  - 2000
Y2  - September 2000
UR  - http://www.nber.org/papers/t0262
L1  - http://www.nber.org/papers/t0262.pdf
N1  - Author contact info:
James J. Heckman
Department of Economics
The University of Chicago
1126 E. 59th Street
Chicago, IL 60637
Tel: 773/702-0634
Fax: 773/702-8490
E-Mail: jheckman@uchicago.edu
M1  - published as Aakvik, Arild, James J. Heckman and Edward J. Vytlacil. "Estimating Treatment Effects For Discrete Outcomes When Responses To Treatment Vary: An Application To Norwegian Vocational Rehabilitation Programs," Journal of Econometrics, 2005, v125(1-2,Mar-Apr), 15-51.
AB  - This paper formulates an econometric framework for studying the impact of interventions on discrete outcomes when responses to treatment vary among observationally identical persons.  Using a latent variable model that can be linked to well-posed economic models, we show how to define and interpret the average treatment effects, the average effect of treatment on the treated, the marginal treatment effect and the distribution of treatment effects for discrete outcomes.  To estimate these parameters and the distribution of treatment effects, we formulate and estimate a discrete choice model with unobservables generated by a factor structure model. We apply our methods to evaluate the effect of Norwegian Vocational Rehabilitation training programs on employment outcomes for women.  We find that applicants to these programs who participate in active training have a 4.6% higher employment rate than nonparticipants.  When we control for the observable characteristics of applicants, we find that the average treatment effects falls to 4.1%.  When we control for the unobservables characteristics of applicants, the average treatment effect falls to -1.4% and effect of treatment on the treated is -11%.  We also find evidence of substantial heterogeneity in response to training.
ER  -