Timing and duration of exposure in evaluations of social programs

Elizabeth M. King () and Jere Richard Behrman

No 4686, Policy Research Working Paper Series from The World Bank

Abstract: Impact evaluations aim to measure the outcomes that can be attributed to a specific policy or intervention. Although there have been excellent reviews of the different methods that an evaluator can choose in order to estimate impact, there has not been sufficient attention given to questions related to timing: How long after a program has begun should one wait before evaluating it? How long should treatment groups be exposed to a program before they can be expected to benefit from it? Are there important time patterns in a program's impact? Many impact evaluations assume that interventions occur at specified launch dates and produce equal and constant changes in conditions among eligible beneficiary groups; but there are many reasons why this generally is not the case. 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.

Keywords: Primary Education; Health Monitoring&Evaluation; Poverty Monitoring&Analysis; Education For All; ICT Policy and Strategies (search for similar items in EconPapers)
New Economics Papers: this item is included in nep-ppm
Date: 2008-08-01
View list of references

Downloads: (external link)
http://www-wds.worldbank.org/servlet/WDSContentSer ... ered/PDF/WPS4686.pdf (application/pdf)

Related works:
Journal Article: Timing and Duration of Exposure in Evaluations of Social Programs (2009)
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: http://EconPapers.repec.org/RePEc:wbk:wbrwps:4686

Access Statistics for this paper

More papers in Policy Research Working Paper Series from The World Bank
Address: 1818 H Street, N.W., Washington, DC 20433
Contact information at EDIRC.
Series data maintained by Roula I. Yazigi ().