NotesFAQContact Us
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ1015416
Record Type: Journal
Publication Date: 2013-Sep
Pages: 14
Abstractor: As Provided
ISSN: ISSN-1098-2140
Using Symmetric Predication of Endogenous Subgroups for Causal Inferences about Program Effects under Robust Assumptions: Part Two of a Method Note in Three Parts
Bell, Stephen H.; Peck, Laura R.
American Journal of Evaluation, v34 n3 p413-426 Sep 2013
To answer "what works?" questions about policy interventions based on an experimental design, Peck (2003) proposes to use baseline characteristics to symmetrically divide treatment and control group members into subgroups defined by endogenously determined postrandom assignment events. Symmetric prediction of these subgroups in both experimental arms ensures the internal validity of the subgroup impacts estimates but leaves the external validity of the findings in doubt. A final step of the procedure solves for impacts on "actual" subgroups using a system of equations that is underidentified without further assumptions. We address these assumptions by first extending the methodology to encompass three rather than two endogenous subgroups and then proposing plausible assumptions for deriving impacts for actual endogenous subgroups. We also consider how the first-stage prediction process can be structured to better support the accuracy of the assumptions. (Contains 6 notes and 4 figures.)
SAGE Publications. 2455 Teller Road, Thousand Oaks, CA 91320. Tel: 800-818-7243; Tel: 805-499-9774; Fax: 800-583-2665; e-mail:; Web site:
Publication Type: Reports - Evaluative; Journal Articles
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A