Journal Article

Timing and Duration of Exposure in Evaluations of Social Programs

Elizabeth M. King and Jere R. Behrman

in The World Bank Research Observer

Published on behalf of World Bank

Volume 24, issue 1, pages 55-82
Published in print February 2009 | ISSN: 0257-3032
Published online February 2009 | e-ISSN: 1564-6971 | DOI:
Timing and Duration of Exposure in Evaluations of Social Programs

More Like This

Show all results sharing this subject:

  • Development Planning and Policy


Show Summary Details


Impact evaluations aim to measure the outcomes that can be attributed to a specific policy or intervention. While there have been excellent reviews of the different methods for estimating impact, insufficient attention has been paid to questions related to timing: How long after a program has begun should it be evaluated? For how long should treatment groups be exposed to a program before they benefit from it? Are there time patterns in a program's impact? This paper examines the evaluation issues related to timing, and discusses the sources of variation in the duration of exposure within programs and their implications for impact estimates. It reviews the evidence from careful evaluations of programs (with a focus on developing countries) on the ways that duration affects impacts.

Journal Article.  10665 words.  Illustrated.

Subjects: Development Planning and Policy

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.