106
Impact Evaluations and Randomization Riza Halili Policy Associate IPA Philippines Impact Evaluation of Social Development Programs June 20, 2018

Impact Evaluations and

  • Upload
    others

  • View
    1

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Impact Evaluations and

Impact Evaluations and

Randomization

Riza Halili

Policy Associate

IPA Philippines

Impact Evaluation of Social

Development Programs

June 20, 2018

Page 2: Impact Evaluations and

1. Impact Evaluations and Randomization

2. How to Randomize

3. RCTs Start to Finish

Overview

June 20, 2018

Page 3: Impact Evaluations and

Presentation Overview

• Introducing Innovations for Poverty Action

• Theory of change, indicators (monitoring), and

impact evaluation

• Causality and impact

• Impact evaluation methods: Non-experimental

and Experimental

• Conclusions

Page 4: Impact Evaluations and

Presentation Overview

• Introducing Innovations for Poverty Action

• Theory of change, indicators (monitoring), and

impact evaluation

• Causality and impact

• Impact evaluation methods: Non-experimental

and Experimental

• Conclusions

Page 5: Impact Evaluations and

Th

e

Pro

ble

m

Ou

r

So

luti

on

Page 6: Impact Evaluations and

OUR VISIONMore evidence, less poverty

Page 7: Impact Evaluations and

IPA’s Approach

We generate insights on what works and what does not through

randomized evaluations, and ensure that those findings will be useful

to, and used by practitioners and policy makers.

ABOUT IPA

Page 8: Impact Evaluations and

• 425 completed projects

• 431 ongoing projects

• 50+ countries

• 400+ leading academics

• 400+ partner organizations (public, private,

and non-profit sectors)

• 20 country offices

IPA Stats

Page 9: Impact Evaluations and

ABOUT IPA

Page 10: Impact Evaluations and

WE WORK ACROSS SECTORS

Financial services Health Agriculture

Education Governance & DemocracySmall & Medium

Enterprises

Page 11: Impact Evaluations and

Focusing on

the Local

• 20 countries

with a

long-term

presence

• Widely

recognized

as the

experts in

field-based

randomized

evaluations

Page 12: Impact Evaluations and

ABOUT IPA-PH • Agrarian Reform (CARP)

• Agricultural Micro-insurance

• Kalahi-CIDSS

• KASAMA (child labor)

• Labeled Remittances

• Special Program for the Employment of Students (SPES)

• SME Credit Scoring

• Court descongestion

• Micro-savings

• Micro-credit

• Combating Vote-Selling

• Values education

• Graduation of the ultra-poor

• Rules of Thumb Financial Literacy

PROJECTS

Page 13: Impact Evaluations and

ABOUT IPA-PH• Bank of the Philippine Islands

• Department of Agrarian Reform

• International Care Ministries

• Philippine Crop Insurance Corp.

• Department of Social Welfare and Development

• Development Bank of the Philippines

• Department of Labor and Employment

• Department of Education

• Supreme Court

• Office of the Vice President

• Negros Women for Tomorrow Foundation

• First Macro Bank

• Asian Development Bank

• National Economic Development Authority

PARTNERS

Page 14: Impact Evaluations and

In the News

• IPA “has succeeded in bringing complex issues in aid and development to the forefront of global development media coverage.”

• -The Guardian

Page 15: Impact Evaluations and

Presentation Overview

• Introducing Innovations for Poverty Action

• Theory of change, indicators (monitoring),

and impact evaluation

• Causality and impact

• Impact evaluation methods: Non-experimental

and Experimental

• Conclusions

Page 16: Impact Evaluations and

Components of Program Evaluation

• Needs Assessment

• Program Theory Assessment

• Process Evaluation

• Impact Evaluation

• Cost Effectiveness

• What is the problem?

• How, in theory, does the program fix the problem?

• Does the program work as planned?

• Were its goals achieved?The magnitude?

• Given magnitude and cost, how does it compare to alternatives?

Page 17: Impact Evaluations and

Levels of Program Evaluation

Needs Assessment

Program Theory Assessment

Process evaluation

Impact evaluation

Cost-benefit / Cost-effectiveness analysis

Page 18: Impact Evaluations and

Components of Program Evaluation

• Needs Assessment

• Program Theory

Assessment

• Process Evaluation

• Impact Evaluation

• Cost Effectiveness

• What is the problem?

• How, in theory, does the

programme fix the problem?

• Does the programme work as

planned?

• Were its goals achieved?

The magnitude?

• Given magnitude and cost, how

does it compare to alternatives?

Imp

lem

en

tati

on

Co

ncep

tuali

zin

g

An

d D

esi

gn

ing

Pro

gra

mm

e

Ass

ess

men

t

Build a Theory of Change

Page 19: Impact Evaluations and

What is a Theory of Change

(ToC)?

• An explanation of how something is made different

• Definition

–A theory of change is a structured approach used in the

design and evaluation of social programs to explore change

and how it happens. It maps the logical chain of how

program inputs achieve changes in outcomes.

–An on-going process of reflection to explore change and how

it happens – and what that means in a particular context,

sector, and/or group of people.

–Guide for what we need to monitor and evaluate

Theory of change is a PROCESS and a PRODUCT.

Page 20: Impact Evaluations and

Causal Hypothesis

Do changes in one variable cause changes in another variable?

Q: How do I expect results to be achieved?

A: If [inputs] produce [outputs] this should lead to [outcomes]

which will ultimately contribute to [goal].

Page 21: Impact Evaluations and

Inputs/

Program Activities

OutputsIntermediate

outcomesImpact

What we do as a

part of the

Program - deliver,

teach, offer loans,

etc.

Tangible

products or

services

produced as a

result of the

activities -

usually can be

counted.

Short-term

behavioral

changes that

result from the

outputs -

preventive

health habits,

usage of tablets.

Long-term

changes that

result from

outcomes –

the result of

the Program.

Theory of Change Components

Page 22: Impact Evaluations and

6 Steps to Building a ToC

1. Situation analysis – Specifying the context

2. Clarify the Program goal

3. Design the Program/product

4. Map the causal pathway

5. Explicate assumptions

6. Design SMART indicators

Page 23: Impact Evaluations and

Building a Theory of Change

Situation/Context Analysis: High health worker absenteeism, low value of immunization,

limited income and time

Increased

Immuni-

zation

Incentives for

Immunization

Camps are

reliably Open

Parents bring

children to

the camps

Parents bring

children to

the camps

repeatedly

GOALOUTPUT OUTCOME

Immunization

Camps

Incentives are

delivered

INPUT

Page 24: Impact Evaluations and

ToC: Explicate Assumptions

• Definition

– Hypotheses about factors or risks which could affect

the progress or success of an intervention

• Intervention results depend on whether or not

the assumptions made, prove to be correct

• Assumptions are the key to unlocking theory of

change thinking

• Source: http://www.unaids.org/sites/default/files/sub_landing/files/11_ME_Glossary_FinalWorkingDraft.pdf

Page 25: Impact Evaluations and

I

N

C

R

E

A

S

E

D

I

M

M

U

N

I

Z

A

T

I

O

N

Theory of Change: Assumptions

Incentives for

Immunization Parents bring

children to the

camps

Immunization

Camps Camp provides

immunizations

Parents value

incentives

Parents trust

camps

Incentives paid

regularly

Situation/Context Analysis: High health worker absenteeism, low value of immunization,

limited income and time

GOAL

Page 26: Impact Evaluations and

• Indicators for each component

–goal, outcome, output, input

• Risk indicators

– Measure whether assumptions and risks have

been met and are facilitating

ToC: Design indicators

Page 27: Impact Evaluations and

Indicators: What are they?

Indicators are:

–A measurement of achievement or change.

How do we know that we are achieving the results we set

out to achieve?

Page 28: Impact Evaluations and

Indicators vs. targets

• Indicators

• Progress markers

• What do we measure? Track?

• Targets

• What are our goals? What change do we expect to see? In what time frame?

• Non-directional vs. directional– Indicator: measures change

– Target: tells us whether change should go up or down

• Time-bound– Indicator: may or may not specify time period

– Target: tells us by when we should expect to see change

Page 29: Impact Evaluations and

Indicators vs. targets

Components of an indicator:

Component Example

What is to be measured Farmers adopting sustainable farming practices

Unit of measurement % of farmers

Quality or standard of the change to be achieved

# of practices adopted by farmers

Target population Farmers benefited by the program

% of farmers employing at least 3 sustainable farming practices.

Page 30: Impact Evaluations and

Indicators vs. targets

Additional components of a target:

Component Example

Baseline status From 20%

Size, magnitude or dimension of change Increase to 50%

Time-frame 1 year after the training

Increase the % of farmers who employ at least 3 sustainable farming techniques from 20% to 50% one year after the training.

Page 31: Impact Evaluations and

Objective vs. subjective indicators

• Objective

– Observed

– Information collected will be the same if collected by different people

– Can be quantitative

• Subjective

– Reported by beneficiary/respondent

– Measured using judgment or perception

Example:

Kg of rice harvested vs. kg of rice harvested as reported by farmer

Page 32: Impact Evaluations and

Quantitative vs. Qualitative

indicators

• Quantitative:

–Statistical measures

–#, %, rate, ratio

–Easily aggregated and compared

Examples:

• # of trainings held

• % of farmers adopting sustainable farming practices

• # of trees planted per household

Page 33: Impact Evaluations and

Quantitative vs. Qualitative

indicators

• Qualitative:– Capture judgments and perceptions

• “quality of”

• “extent of”

• “compliance with”

• “satisfaction with”

– Can be quantified and compared• E.g. scale to measure teaching quality

• E.g. scale to measure youth perceptions of self-efficacy

• Hint: Use pre-existing scales and indicators!

Examples:• % of participants who rated the training as high quality

• Extent to which government supports integrate with local programming

Page 34: Impact Evaluations and

OUTPUT OUTCOME

ToC: Design Indicators

Situation/Context Analysis: High health worker absenteeism, low value of immunization,

limited income and time

INPUT

Increased

Immunization

Rates

Immunization

Camps +

Incentives

Camps are

open and

incentives are

delivered

Parents bring

children to the

camps

Parents bring

children to

the camps

repeatedly

After 6 months, camps were established and equipped to run in 90% of Programme villages. . All health

workers were trained to offer parents the

appropriate incentives at their visit.

After 9 months, camps were running on a monthly basis at 90% of the planned

villages.

Incentives were delivered to these

camps

70-75% of Parents brought children to be

immunized in the camps that were open and reported receiving

incentives.

90 to 95% of parents who immunized the children during the

first round of immunization, brought them to be immunized for the second round

At the end of the Program,

immunization rate was 39% in the

intervention villages as compared to 6%

in comparison villages

GOAL

# of villages camps established

# of trained health workers

# camps open

# camps incentives delivered to

# of beneficiaries attending camps

# of beneficiaries receiving incentives

# of beneficiaries attending camps

repeatedly

# of beneficiaries receiving incentives

# of children immunized

Page 35: Impact Evaluations and

I

N

C

R

E

A

S

E

D

I

M

M

U

N

I

Z

A

T

I

O

N

ToC: Design Indicators

Incentives for

Immunization Parents bring

children to the

camps

Immunization

Camps Camp provides

immunizations

Parents value

incentives

Parents trust

camps

Incentives paid

regularly

Situation/Context Analysis: High health worker absenteeism, low value of immunization,

limited income and time

GOAL# of beneficiaries attending camps

repeatedly

# of beneficiaries receiving incentives

# of incentives bought as reflected in receipts

# of beneficiaries attending camps

repeatedly

# of immunizations administered at the camp site by hired

nurses

Page 36: Impact Evaluations and

ExampleWhat is it? Components Assumptions Conclusion

Why is Theory of Change Important?

For evaluators, reminds us to consider process

For implementers, it helps us be results oriented

Increased Immuni-

zation

Incentives for Immunization

Camps are reliably Open

Parents bring

children to the camps

Parents bring

children to the camps repeatedly

GOALOUTPUT OUTCOME

ImmunizationCamps

Incentives are delivered

INPUT

Page 37: Impact Evaluations and

Inputs Activities Outputs Outcomes Goal

Theory Failure vs. Implementation Failure

Successful intervention

Implementation failure

Theory failure

Inputs Activities Outputs Outcomes Goal

Inputs Activities Outputs Outcomes Goal

Page 38: Impact Evaluations and

Presentation Overview

• Introducing Innovations for Poverty Action

• Theory of change, indicators (monitoring), and

impact evaluation

• Causality and impact

• Impact evaluation methods: Non-experimental

and Experimental

• Conclusions

Page 39: Impact Evaluations and

What is Impact Evaluation?

• Two key concepts…

–Causality

–The counterfactual…what is that?

Impact Evaluation tells you…

The causal effect of a program or activity on

an outcome of interest by comparing the

outcomes of interest (short, medium, or long

term) with what would have happened without

the program—a counterfactual.

Page 40: Impact Evaluations and

What is causality…

and what do we mean by impact?

Page 41: Impact Evaluations and

Which of the following indicates

a causal relationship?

A. A positive correlation between computer aided learning

and test scores

B. A positive correlation between income and health

outcomes

C. A positive correlation between years of schooling and

income

D. None of the above

E. Don’t know

Page 42: Impact Evaluations and

Causality

Cause and effect language is used everyday in a lot of contexts, but it means something very specific in impact evaluation.

• We can think of causality as:

• Isolating the singular effect of a program, independent of any other intervening factors, on an outcome of interest and estimating the size of this effect accurately and with confidence

• We use impact evaluation to rule out the possibility that any other factors, other than the program of interest, are the reason for these changes

Page 43: Impact Evaluations and

Measuring Impact for Pratham’s

Balsakhi Program

Case 2: Remedial Education in IndiaEvaluating the Balsakhi Program

Incorporating random assignment into the program

Case 2: Remedial Education in IndiaEvaluating the Balsakhi Program

Incorporating random assignment into the program

Page 44: Impact Evaluations and

What was the Problem?

▪ Many children in 3rd and 4th standard were not even at

the 1st standard level of competency

▪ Class sizes were large

▪ Social distance between teacher and many of the

students was large

Page 45: Impact Evaluations and

Proposed Solution

▪ Work with Pratham in 124 Municipal Schools in

Vadodara (Western India)

▪ Hire local women (Balsakhis) from the

community

▪ Train them to teach remedial competencies

• Basic literacy, numeracy

▪ Identify lowest performing 3rd and 4th standard

students

• Take these students out of class (2 hours/day)

• Balsakhi teaches them basic competencies

Page 46: Impact Evaluations and

Setting up the impact evaluation

• Implemented over 2 years

• Outcome of interest: test scores

Page 47: Impact Evaluations and

UNDERSTANDING

IMPACTP

rim

ary O

utc

om

e

Time

Program starts

A. POSITIVE

B. NEGATIVE

C. ZERO

D. DON’T

KNOW

What is the impact of the Balsakhi program?

Page 48: Impact Evaluations and

UNDERSTANDING

IMPACTP

rim

ary O

utc

om

e

Time

Program starts

What is the impact of the Balsakhi program?

Impact

Page 49: Impact Evaluations and

▪ Impact is defined as a comparison between:

• The outcome some time after the program has been introduced

• The outcome at that same point in time had the program not been introduced

This is know as the “Counterfactual”

How to Measure Impact?

54

Page 50: Impact Evaluations and

UNDERSTANDING

IMPACT

In other words, impact evaluation measures…

How lives have changed(with the program)

compared to how they would have changed

(without the program)

IMPACT of the program

KEY

Page 51: Impact Evaluations and

UNDERSTANDING

IMPACT

compared to how they would have changed

(without the program)

Counterfactual: represents the state of the world that program participants would have experienced in the absence of the program (i.e. had they not participated in the program)

Page 52: Impact Evaluations and

Impact: What is it?

Time

Pri

mar

y O

utc

om

e

ImpactIntervention

Page 53: Impact Evaluations and

Impact: What is it?

Time

Pri

mar

y O

utc

om

e

Impact

Intervention

Page 54: Impact Evaluations and

UNDERSTANDING

IMPACT

compared to how they would have changed

(without the program)

Counterfactual: represents the state of the world that program participants would have experienced in the absence of the program (i.e. had they not participated in the program)

Problem: Counterfactual cannot be observed

Solution: We need to “mimic” or construct the counterfactual

Page 55: Impact Evaluations and

Presentation Overview

• Introducing Innovations for Poverty Action

• Theory of change, indicators (monitoring), and

impact evaluation

• Causality and impact

• Impact evaluation methods: Non-

experimental and Experimental

• Conclusions

Page 56: Impact Evaluations and

MEASURING

IMPACT

How can we “mimic” or construct the counterfactual?

Select a comparison group not affected by the program.

RandomizedUse random assignment of the program to create a control group which mimics the counterfactual.

Non-randomizedArgue that a certain excluded group mimics the counterfactual.

Page 57: Impact Evaluations and

MEASURING

IMPACT

Methods:• Pre-post• Simple difference• Difference-in-differences• Multivariate regression• Statistical Matching• Interrupted Time Series• Instrumental Variables• Regression Discontinuity• Randomized controlled trials

Non-randomized

Randomized

Page 58: Impact Evaluations and

MEASURING

IMPACT

Methods:• Pre-post• Simple difference• Difference-in-differences• Multivariate regression• Statistical Matching• Interrupted Time Series• Instrumental Variables• Regression Discontinuity• Randomized controlled trials

Non-randomized

Randomized

Page 59: Impact Evaluations and

MEASURING

IMPACT

An impact evaluation is only as good as the comparison group it uses to mimic the counterfactual.

For each evaluation method, ask yourself:

1. What is the comparison group?

2. What assumptions must be valid in order for the comparison group to accurately represent the counterfactual?

INTERNAL VALIDITY

Page 60: Impact Evaluations and

UNDERSTANDING

IMPACT

2. What assumptions must be valid in order for the comparison group to accurately represent the counterfactual?

INTERNAL VALIDITY

Objectives Achievement: What intended outputs and outcomes/impact

were found and to what extent can they be attributed to

project/program activities?

Annex A: Evaluation Criteria, NEDA-DBM Joint Memorandum Circular No. 2015-01

…ensure that evaluations are conducted with the highest possible degree

of impartiality in order to maximize objectivity and minimize the potential

for bias.

Annex E: Impartiality, NEDA-DBM Joint Memorandum Circular No. 2015-01

Page 61: Impact Evaluations and

MEASURING

IMPACT

Case Study: Pratham’s Balsakhi Program

Case 2: Remedial Education in IndiaEvaluating the Balsakhi Program

Incorporating random assignment into the program

Case 2: Remedial Education in IndiaEvaluating the Balsakhi Program

Incorporating random assignment into the program

Page 62: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post

Simple difference

Difference-in-differences

Multivariate regression

Randomized ControlledTrial

Page 63: Impact Evaluations and

MEASURING

IMPACT: PRE-POST

Before After

One of the most common methods for determining impact.

Compare data for program participants BEFORE and AFTERthe intervention.

Page 64: Impact Evaluations and

MEASURING

IMPACT: PRE-POST

Balsakhi Program: Outcomes

• You are tasked to conduct a pre-post evaluation of the balsakhi program on at-risk children, evaluating the impact of the program on test scores.

1. What is the comparison group in this evaluation?

2. What are the potential problems with this evaluation? I.e, what assumptions must be true in order for the comparison group to be valid?

Page 65: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post Program participants before participating in the program

Simple difference

Difference-in-differences

Multivariate regression

Randomized ControlledTrial

Page 66: Impact Evaluations and

MEASURING

IMPACT: PRE-POST

24.8

51.22

0

10

20

30

40

50

60

Start of program End of program

Average test scores of Balsakhi students

Average post-test score for children with a Balsakhi 51.22

Average pretest score for children with a Balsakhi 24.80

Difference 26.42

26.42

Page 67: Impact Evaluations and

Balsakhi program Test scores

MEASURING

IMPACT: PRE-POST

Page 68: Impact Evaluations and

Balsakhi program Test scores

school feeding program

MEASURING

IMPACT: PRE-POST

Page 69: Impact Evaluations and

Balsakhi program Test scores

school feeding program

free uniforms

MEASURING

IMPACT: PRE-POST

Page 70: Impact Evaluations and

Balsakhi program Test scores

school feeding program

free uniforms

potable water system installed

MEASURING

IMPACT: PRE-POST

Page 71: Impact Evaluations and

Balsakhi program Test scores

school feeding program

free uniforms

conditional cash transfers

potable water system installed

MEASURING

IMPACT: PRE-POST

Page 72: Impact Evaluations and

Balsakhi program Test scores

school feeding program

free uniforms

conditional cash transfers

new textbooks

Natural maturity / increased cognitive skills over time

potable water system installed

good harvest

Teacher trainings

Improved roads

MEASURING

IMPACT: PRE-POST

Page 73: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post Program participants before participating in the program

The program was the only factor influencing outcomes over time

26.42*

Simple difference

Difference-in-differences

Multivariate regression

Randomized ControlledTrial

Page 74: Impact Evaluations and

MEASURING

IMPACT: SIMPLE DIFFERENCE

Non-participants

Measures the difference between program participants and non-participants after the program is completed.

Participants

Program starts

Page 75: Impact Evaluations and

MEASURING

IMPACT: SIMPLE DIFFERENCE

Balsakhi Program: Outcomes

• You are tasked to conduct a simple difference evaluation of the balsakhi program, evaluating the impact of the program on test scores.

1. What is the comparison group in this evaluation?

2. What are the potential problems with this evaluation? I.e, what assumptions must be true in order for the comparison group to be valid?

Page 76: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post Program participants before participating in the program

The program was the only factor influencing outcomes over time

26.42*

Simple difference Non-participants from whom we have outcome data

Difference-in-differences

Multivariate regression

Randomized ControlledTrial

Page 77: Impact Evaluations and

MEASURING

IMPACT: SIMPLE DIFFERENCE

56.2751.22

0

10

20

30

40

50

60

Not enrolled in program Enrolled in program

Average test scores end of program

Average score for children with a balsakhi 51.22

Average score for children without a balsakhi 56.27

Difference -5.05

-5.5

Page 78: Impact Evaluations and

MEASURING

IMPACT: SIMPLE DIFFERENCE

Selection effect

• Self-selection: those who voluntarily join program likely to be different than those who don’t (e.g. more motivation, access, etc.)

• Administrative selection:administrators select participants based on certain criteria

• Treatment and comparison groups are not comparable

Page 79: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post Program participants before participating in the program

The program was the only factor influencing outcomes over time

26.42*

Simple difference Nonparticipants from whom we have outcome data

Participants and nonparticipants are identical except for program participation (i.e. no selection effect)

Difference-in-differences

Multivariate regression

Randomized ControlledTrial

Page 80: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post Program participants before participating in the program

The program was the only factor influencing outcomes over time

26.42*

Simple difference Nonparticipants from whom we have outcome data

Participants and nonparticipants are identical except for program participation (i.e. no selection effect)

-5.05*

Difference-in-differences

Multivariate regression

Randomized ControlledTrial

Page 81: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCES

Non-participants

Combines simple difference and pre-post approaches.

Participants

Program starts

Participants

Non-participants

Measures changes in outcomes over time of program participants relative to the changes in outcomes of nonparticipants.

Page 82: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCESP

rim

ary O

utc

om

e

Time

Program starts

24.8

51.2

Page 83: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCESP

rim

ary O

utc

om

e

Time

Program starts

24.8

51.256.27

36.67

Page 84: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCESP

rim

ary O

utc

om

e

Time

Program starts

IMPACT =-5.05 – (-11.87) =

6.82T-C = -11.87

T-C = -5.05

Page 85: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCES

Pretest Post-test Difference

Average score for children with a balsakhi(treatment)

24.80 51.22 26.42

Average score for children without a balsakhi(comparison)

Difference

36.67 56.27 19.60

6.82-11.87 -5.05

Page 86: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCEST

est

Sco

res

Time

Program starts

Parallel Trends Assumption

Differences between treatment and comparison groups do not have more or less of an effect on outcomes over time.

Differences have constant effect on outcomes.

10

10

Page 87: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCEST

est

Sco

res

Time

Program starts

Parallel Trends Assumption

Differences between treatment and comparison groups have constant effect on outcomes.

10

24

X

Page 88: Impact Evaluations and

MEASURING

IMPACT: DIFFERENCE-IN-DIFFERENCES

Balsakhi Program: Outcomes

• You are tasked to conduct a double difference evaluation of the balsakhi program on at-risk children, evaluating the impact of the program on test scores.

1. What is the comparison group in this evaluation?

2. What are the potential problems with this evaluation? Be specific.

Page 89: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post Program participants before participating in the program

The program was the only factor influencing outcomes over time

26.42*

Simple difference Nonparticipants from whom we have outcome data

Participants and nonparticipants are identical except for program participation (i.e. no selection effect)

-5.05*

Difference-in-differences Nonparticipants from whom we have outcome data before and after the program

If program wasn’t implemented, two groups would have identical trajectories

6.82*

Multivariate regression

Randomized ControlledTrial

Page 90: Impact Evaluations and

MEASURING

IMPACT: MULTIVARIATE REGRESSION

Non-participants Participants

Program starts Like simple difference, but…

“control” for factors that might explain differences in outcomes other than the program

Page 91: Impact Evaluations and

MEASURING

IMPACT: MULTIVARIATE REGRESSION

Non-participants Participants

Program starts Like simple difference, but…

“control” for factors that might explain differences in outcomes other than the program

explanatory variables (age, income, education, etc.)

Page 92: Impact Evaluations and

MEASURING

IMPACT: MULTIVARIATE REGRESSIONEvaluation method Comparison group Assumptions Balsakhi mpact

estimate

Pre-post Program participants before participating in the program

The program was the only factor influencing outcomes over time

26.42*

Simple difference Nonparticipants Participants and nonparticipants are identical except for program participation (i.e. no selection effect)

-5.05*

Difference-in-differences

Nonparticipants before and after the program

If program wasn’t implemented, two groups would have identical trajectories

6.82*

Multivariate regression Nonparticipants All observable differences controlled for, no unobservable differences that affect outcome

1.92

Page 93: Impact Evaluations and

MEASURING

IMPACT: OTHER METHODS

There are more non-experimental methods to estimate program impacts:• Statistical matching• Regression discontinuity design (RDD)• Instrumental variables• Interrupted time series

Common thread: all try to mimic the counterfactual to estimate impact.

Problem: assumptions are not testable

Page 94: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTS

Also known as:

• Randomized Controlled Trials (RCTs)• Randomized Assignment Studies• Randomized Field Trials• Social experiments• Randomized Controlled Experiments

Page 95: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTS

Program

candidates

Outcomes of

interestRandomly split

into 2 groups

INTERVENTION

NO INTERVENTION

TREATMENT GROUP

CONTROL GROUP

Page 96: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTS

KEY ADVANTAGE

Because members of the groups (treatment and control) do not differ systematically at the outset of the experiment,

any difference that subsequently arises between them can be attributed to the program rather than to other factors.

Page 97: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTS

What’s the difference between random selection and random assignment?

Page 98: Impact Evaluations and

Target

Population

Not in

evaluation

Evaluation

Sample

Total

Population

Random

Assignment

Treatment

Group

Control

Group

MEASURING

IMPACT: RANDOMIZED EXPERIMENTS

EXTERNAL VALIDITY INTERNAL VALIDITY

Page 99: Impact Evaluations and

Randomly

sample

from both

program and

control

Randomly

assign

to program

and control

Randomly

sample

from area of

interest

Page 100: Impact Evaluations and

Randomly

sample

from both

program and

control

Randomly

assign

to program

and control

Randomly

sample

from area of

interest

Page 101: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTS

• Assignment purely by chance; allocation unrelated to characteristics that affect outcomes

• With large enough number of units, the two groups are statistically identical, on average

• Key advantage: balanced on unobservable characteristics as well as observables

• Any differences that subsequently arise can be attributed to the program rather than other factors

Page 102: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTS

Standard deviation in parentheses. Statistics displayed for Regions I, II, III, IV-A, and V.

*/*/***: Statistically significant at the 10% / 5% / 1% level

Source: Edmonds, et al. (2016). Impact Evaluation of KASAMA Program: Baseline Report.

Evaluation of DOLE’s KASAMA Program: Balance Table

Page 103: Impact Evaluations and

MEASURING

IMPACT: RANDOMIZED EXPERIMENTSEvaluation method Comparison group Assumptions Balsakhi Impact

Estimate

Pre-post Program participants before participating in the program

The program was the only factor influencing outcomes over time

26.42*

Simple difference Nonparticipants from whom we have outcome data

Participants and nonparticipants are identical except for program participation (i.e. no selection effect)

-5.05*

Difference-in-differences Nonparticipants from who we have outcome data before and after the program

If program wasn’t implemented, two groups would have identical trajectories

6.82*

Multivariate regression Nonparticipants All observable differences controlled for, no unobservable differences that affect outcome

1.92

Randomized ControlledTrial

Units randomly assigned to the control group

Assumptions are limited provided the design is strictly followed

5.87*

Page 104: Impact Evaluations and

Presentation Overview

• Introducing Innovations for Poverty Action

• Theory of change, indicators (monitoring), and

impact evaluation

• Causality and impact

• Impact evaluation methods: Non-experimental

and Experimental

• Conclusions

Page 105: Impact Evaluations and

Conclusions

▪ Theory of change as the basis for what to monitor and evaluate

▪ Monitoring is equally important as impact evaluations

▪ There are many ways to estimate a program’s impact

▪ Different methods can generate different estimates

▪ Each evaluation method has specific assumptions and

limitations

▪ If applicable, randomized experiments, when properly designed

and conducted, provide the most credible method to estimate

the impact of a program

Page 106: Impact Evaluations and

More Evidence,

Less Poverty

Innovations for Poverty Action

www.poverty-action.org

[email protected]

Thank you!