Timing and duration of exposure in evaluations of social programs

"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 r...

Full description

Bibliographic Details
Main Author: King, Elizabeth M.
Corporate Author: World Bank
Other Authors: Behrman, Jere R.
Format: eBook
Language:English
Published: [Washington, D.C] World Bank 2008
Series:Policy research working paper
Subjects:
Online Access:
Collection: World Bank E-Library Archive - Collection details see MPG.ReNa
LEADER 02047nmm a2200241 u 4500
001 EB002098287
003 EBX01000000000000001238377
005 00000000000000.0
007 cr|||||||||||||||||||||
008 221013 ||| eng
100 1 |a King, Elizabeth M. 
245 0 0 |a Timing and duration of exposure in evaluations of social programs  |h Elektronische Ressource  |c Elizabeth M. King, Jere R. Behrman 
260 |a [Washington, D.C]  |b World Bank  |c 2008 
653 |a Policy sciences / Evaluation 
700 1 |a Behrman, Jere R. 
710 2 |a World Bank 
041 0 7 |a eng  |2 ISO 639-2 
989 |b WOBA  |a World Bank E-Library Archive 
490 0 |a Policy research working paper 
500 |a Includes bibliographical references. - Title from PDF file as viewed on 5/20/2009 
856 4 0 |u http://elibrary.worldbank.org/content/workingpaper/10.1596/1813-9450-4686  |x Verlag  |3 Volltext 
082 0 |a 330 
520 |a "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. "--World Bank web site