← Search

Quarterly Journal of Economics Vol. 115 No. 2 2000

Substitution and Dropout Bias in Social Experiments: A Study of an Influential Social Experiment

James J. Heckman1,2; N. Hohmann2; Jeffrey A. Smith3; Michael B. C. Khoo4

1 American Bar Foundation · 2 University of Chicago · 3 Western University · 4 National Public Radio

open access

Abstract

This paper considers the interpretation of evidence from social experiments when persons randomized out of a program being evaluated have good substitutes for it, and when persons randomized into a program drop out to pursue better alternatives. Using data from an experimental evaluation of a classroom training program, we document the empirical importance of control group substitution and treatment group dropping out. Evidence that one program is ineffective relative to close substitutes is not evidence that the type of service provided by all of the programs is ineffective, although that is the way experimental evidence is often interpreted.

DOI
10.1162/003355300554764
Volume
115
Issue
2
Pages
651-694
Language
en
Sources
bibtex:phds-export.bib openalex crossref

Cite