The Campbell Collaboration www.campbellcollaboration.org Howard White CEO, Campbell Collaboration What evidence should policy makers use and how can we make it happen?
The Campbell Collaboration www.campbellcollaboration.org
Howard White
CEO, Campbell Collaboration
What evidence should policy makers use
and how can we make it happen?
The Campbell Collaboration www.campbellcollaboration.org
Things we probably all agree on
• Large n impact evaluation cannot answer all the questions we have
about how to ‘do development’
• … or even about programme effectiveness
• Rigorous impact evaluation should NOT be carried out on every project
• Rigorous impact evaluate can rarely be used to evaluate a whole
project
• This is partly as large n designs are not always applicable
• And many RCTs to date focus on whacky gimmicks, not things of
interest to policymakers (‘researcher capture’)
… But despite all that we are not doing enough
‘development RCTs’
The Campbell Collaboration www.campbellcollaboration.org
So what can impact evaluations be used for?
Using IE to measure results:
• Alignment, attribution and
aggregation
• Representative sample
• Agency incentive
structures
Accountability Lesson
learning
• Second generation questions
• Build in learning opportunities
• Causal chain analysis
• Accumulate bodies of evidence:
the role of systematic reviews
Implies strategic selection of IE cases
for lesson learning
The Campbell Collaboration www.campbellcollaboration.org
Second generation questions don’t ask ‘does it
work’ but design questions about ‘how can it work
better?’
E.g. conditional cash transfer second generation questions:
– Conditions or not?
– What sort of conditions?
– Who to give money to?
– How to give the money?
– When and how often to give money?
The Campbell Collaboration www.campbellcollaboration.org
The largest growth in RCTs has been in the private sector: small, rapid studies to improve performance
DVD price experiment
Up to US$15 difference for same product
Reimbursed those who paid more, and now all pay lowest price even if order at higher price
Maximizing click through
Variations in home page layout.
Impact evaluation takes one hour
Mergers and Acquistions
80% of M&A bad for bottom line
Cisco tripled profits through 60 M&A
Exploited heterogeneity
Had data on 9,000 cases
5
Researchers working in
partnership with private sector:
• Product placement in super
markets in low-income areas for
healthy choices
• Improving efficiency of water use
in Atlanta
• Front of pack nutrition labelling
and healthy eating
The Campbell Collaboration www.campbellcollaboration.org
And this really matters… as most things don’t work
80% of businesses fail in first five years
– do we really think development
projects any better?
But there is usually no bottom line for
development projects
Impact evaluation is the bottom line.
And here is what the bottom line says in
developed countries:
• Education: 90 interventions evaluated in
RCTs by IES - 90% had weak or no positive
effects.
• Employment/training: Department of Labor-
commissioned RCTs 75% weak or no
positive effects
• Business: Over 13,000 RCTs of new
products/strategies conducted by Google
and Microsoft, 80- 90% no significant
effects.
Without impact evaluation you can move the
bottom line!
The Campbell Collaboration www.campbellcollaboration.org
Rapid impact evaluation as formative research: 3ie’s HIV programme (VMMC)
7
• Soccer-related incentives: Food voucher
• Transportation reimbursement and framing
messages
• Pregnant women delivering information to
male partners
• Smartphone raffle
• SMS messages
• Conditional cash transfer for peer referral
The Campbell Collaboration www.campbellcollaboration.org
=𝑇𝑜𝑡𝑎𝑙 𝑒𝑓𝑓𝑒𝑐𝑡
𝑁𝑜. 𝑝𝑎𝑟𝑡𝑖𝑐𝑖𝑝𝑎𝑡𝑖𝑛𝑔
𝑁𝑜.𝑝𝑎𝑟𝑡𝑖𝑐𝑖𝑝𝑎𝑡𝑖𝑛𝑔
𝑁𝑜.𝑜𝑓 𝑖𝑛𝑡𝑒𝑛𝑑𝑒𝑑 𝑏𝑒𝑛𝑒𝑓𝑖𝑐𝑎𝑟𝑖𝑒𝑠
𝐴𝑇𝐸 (𝐼𝑇𝑇) =𝑇𝑜𝑡𝑎𝑙 𝑒𝑓𝑓𝑒𝑐𝑡
𝑁𝑜. 𝑜𝑓 𝑖𝑛𝑡𝑒𝑛𝑑𝑒𝑑 𝑏𝑒𝑛𝑒𝑓𝑖𝑐𝑎𝑟𝑖𝑒𝑠
= 𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡 𝑜𝑓 𝑡𝑟𝑒𝑎𝑡𝑒𝑑 𝑒𝑓𝑓𝑒𝑐𝑡 𝑇𝑜𝑇 𝑥 𝑃𝑎𝑟𝑡𝑖𝑐𝑖𝑝𝑎𝑡𝑖𝑜𝑛 𝑟𝑎𝑡𝑒 (𝑃𝑅)
So the participation rate is a key
determinant of effectivenessAnd participation is often
far less than we expect
The importance of causal chain analysis
The Campbell Collaboration www.campbellcollaboration.org
The funnel of attrition Only these people
may experience
improved outcomes
The Campbell Collaboration www.campbellcollaboration.org
Does the community participate?
0
20
40
60
80
100
Heard of project Aware of meeting Attended meeting Spoke at meeting Aware of cost of project
BRA-KDP MASAF Tuungane GoBifo ZAMSIF
JSIF FISE PAMR FUMAC Average
Community participation declines by degree of engagement:
the funnel of attrition
The Campbell Collaboration www.campbellcollaboration.org
Many interventions fall at the first hurdle
• Free male circumcision: 25% if
free down to just 10% with
partial subsidy
• Pre-school in Mexico, fewer
than 10% of parents who
registered actually took part
• Insurance schemes typically
less than 10% take up
The Campbell Collaboration www.campbellcollaboration.org
And participation declines over time
• ½ households stopped using
improved cookstoves by 8
month follow up survey
• Water treatment: fewer than
1/3 households using filters in
Cambodia and pasteurising in
Kenya after 3-4 years.. And
only 5% disinfecting in
Guatemala after just one year
The Campbell Collaboration www.campbellcollaboration.org
The role of systematic reviews: can send messages on what
does and doesn’t work
In fragile and conflict-affected states (FCS), the approach has also
helped rebuild social capital and trust within communities, and between
communities and governments
World Bank CDD Website
NOTE: Weights are from random effects analysis
Overall (I-squared = 48.9%, p = 0.014)
PAC
Armenia SIF
FHIS 2
FISE
JSIF
GoBifo
PAMR
FUMAC
KALAHI-CIDSS
MASAF
project
KDP
CDR
ZAMSIF
BRA-KDP
FUMAC-P
Tuungane
Brazil
Armenia
Honduras
Nicaragua
Jamaica
Sierra Leone
Benin
Brazil
Philipines
Malawi
country
Indonesia
Liberia
Zambia
Indonesia
Brazil
DRC
0.06 (-0.01, 0.14)
-0.12 (-0.58, 0.34)
0.09 (-0.02, 0.20)
0.48 (0.24, 0.71)
-0.04 (-0.85, 0.76)
0.50 (-0.01, 1.01)
0.14 (-0.19, 0.48)
0.17 (-0.05, 0.39)
-0.03 (-0.32, 0.26)
0.02 (-0.14, 0.18)
-0.27 (-0.62, 0.09)
d (95% CI)
0.22 (-0.10, 0.53)
0.06 (-0.08, 0.20)
-0.02 (-0.33, 0.30)
-0.03 (-0.43, 0.38)
-0.28 (-0.58, 0.03)
0.01 (-0.05, 0.07)
100.00
2.48
13.04
6.87
0.90
2.07
4.18
7.34
5.05
10.17
3.79
%
Weight
4.58
11.31
4.60
3.05
4.82
15.74
0.06 (-0.01, 0.14)
-0.12 (-0.58, 0.34)
0.09 (-0.02, 0.20)
0.48 (0.24, 0.71)
-0.04 (-0.85, 0.76)
0.50 (-0.01, 1.01)
0.14 (-0.19, 0.48)
0.17 (-0.05, 0.39)
-0.03 (-0.32, 0.26)
0.02 (-0.14, 0.18)
-0.27 (-0.62, 0.09)
d (95% CI)
0.22 (-0.10, 0.53)
0.06 (-0.08, 0.20)
-0.02 (-0.33, 0.30)
-0.03 (-0.43, 0.38)
-0.28 (-0.58, 0.03)
0.01 (-0.05, 0.07)
100.00
2.48
13.04
6.87
0.90
2.07
4.18
7.34
5.05
10.17
3.79
%
Weight
4.58
11.31
4.60
3.05
4.82
15.74
CDD reduces cohesion CDD increases cohesion
0-.5 0 .5
Social cohesion
The Campbell Collaboration www.campbellcollaboration.org
Poor assumptions: payment for environmental services
Tiny effect
0.3 % reduction in
deforestation
i.e. after 10 years 97% of
land for which
payments received
would still have been
forested in absence of
the programme
Effects of PES on forest cover change rate due to deforestation
ra - rc
−0.010 −0.005 0.000 0.005 0.010
Costa Rica PSA
Costa Rica PSA
Costa Rica PSA
Mexico PSAH
Mexico MBCF
1998−2005
1997−2000
2000−2005
2004−2006
2000−2009
Arriagada et al. 2011
Pfaff et al. 2008
Robalino et al. 2008
Alix−Garcia et al. 2012
Honey−Roses et al. 2011
Random effects mean
Predictive interval
I2 = 67.9%, t
2 = 0 (0), t = 0
The Campbell Collaboration www.campbellcollaboration.org
But meta-analysis allows us to get at design
features, for example …
CCTs have a larger effect on enrolment rates
• Secondary than primary
• The larger the transfer
• The less frequent the transfer
• If conditions include achievement not just attendance
And…
The Campbell Collaboration www.campbellcollaboration.org
Conditionality works
Children 60% more likely to be in school with conditionality
which is monitored and enforced compared to no
conditions
But we need a lot of primary studies
to exploit heterogeneity
The Campbell Collaboration www.campbellcollaboration.org
The impact of water quality interventions is not
sustained
NOTE: Weights are from random effects analysis
Water supply (12 months or more)
Subtotal
Water quality (under 12 months)
Subtotal
Water quality (12 months or more)
Subtotal
Sanitation (12 months or more)
Subtotal
Hygiene (under 12 months)
Subtotal
Hygiene (12 months or more)
Subtotal
Multiple (under 12 months)
Subtotal
Multiple (12 months or more)
Subtotal
ID
Study
0.82 (0.71, 0.96)
0.56 (0.47, 0.66)
0.81 (0.67, 0.97)
0.64 (0.37, 1.10)
0.72 (0.60, 0.86)
0.67 (0.49, 0.91)
0.41 (0.23, 0.74)
0.77 (0.70, 0.85)
ES (95% CI)
0.82 (0.71, 0.96)
0.56 (0.47, 0.66)
0.81 (0.67, 0.97)
0.64 (0.37, 1.10)
0.72 (0.60, 0.86)
0.67 (0.49, 0.91)
0.41 (0.23, 0.74)
0.77 (0.70, 0.85)
ES (95% CI)
Ratio favours intervention
1.1 .5 .75 1 2
The Campbell Collaboration www.campbellcollaboration.org
Medical progress
There are irreversible
improvements in
medical practice
The Campbell Collaboration www.campbellcollaboration.org
In the 1920s teachers were paid according to their
pupils’ exam results. This system resulted in
classes focused on teaching material of relevance
to the exam to the neglect of other aspects of the
child’s education or overall development.
Fortunately we know better now and such policies
have long been abandoned’
The Campbell Collaboration www.campbellcollaboration.org
i.e. what is our theory of change as to use of
evidence, and how does it differ?
So why is social policy subject to
faddism in a way that medical practice
is not?
Answering that question is
another talk! But…..
The Campbell Collaboration www.campbellcollaboration.org
3ie 50% ‘hit rate’ with primary studies
• Scaling up
• Closing down
• Informing design
• Affecting other programmes
• Institutionalizing lesson learning
Much less to show for systematic
reviews
Why?
• Production process
• Diffuse stakeholders
• More ambitious goals
Solutions:
• Better reviews
• Demand-driven reviews
• More user engagement
• Derivative products
The Campbell Collaboration www.campbellcollaboration.org
Thank you
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