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Why Impact Evaluation

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• Why Impact Evaluation?

“Micro-credit has been changing people's lives and revitalizing communities”

UN, 2005, Year of micro-credit

“More than 200 poor….killed themselves in late 2010, according to media reports compiled by the government of the south

Indian state. The state blamed microfinance companies--which give

small loans intended to lift up the very poor--for fueling a frenzy of over

indebtedness and then pressuring borrowers so relentlessly thatsome took their own lives.”

Wall Street Journal, February 2012

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Why Impact Evaluations?

• Surprisingly little hard evidence on the social programs that actually work

• Decisions often based more on emotion than evidence

• Accountability (for the implementing agency)- Did we do what we said we were going to do?- Did we have a positive impact on people’s lives?

• Lesson learning (for the entire world)– Particular programs do or do not work– What is the most effective route to achieve a certain outcome?– Similarities in strategies that are successful, for example, in

changing behavior, even across fields?

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What makes a good evaluation?

• Answers an important question in an unbiased and definitive way

• To do that you need a model/theory of change (ToC)– Who is the target?– What are their needs?– What is the program seeking to change?– What is the precise program or part of program

being evaluated?

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Example of ToC: provision of textbooks

Needs

Logical FrameworkLong-term Goal

Input Output Outcome Impact

Poor children in Busia district Kenya with low learning, low incomes, few books, can’t take books home, hard to learn.

NGO purchases books.

Books delivered to and used by schools.

Children use books and are able to study better.

Higher test scores

Higher Income

More complex models

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• Ex: delaying the age of first birth– Economic constraints– Lack of access to family planning– Family pressure / Group effects– Ignorance of the dangers for maternal / infant

health• What are adequate programs to address these

issues?– Incentives – for whom?– Symbolic reward – to whom?– Information – for whom?

• Think about constraints, targets, spillovers• Ill-designed programs may have no model at all